Conveyor belt slippage

{
  "publication_number": "US11220116B2",
  "country": "US",
  "kind": "B2",
  "title": "Conveyor belt slippage",
  "abstract": "In one example, a method of controlling a printing system is described, the method comprising activating a driver to advance a conveyor belt in a plurality of sub-turns. For each of the plurality of sub-turns, a first parameter associated with movement of the conveyor belt is determined, based on data obtained from the driver. For each of the plurality of sub-turns, a second parameter associated with movement of the conveyor belt is also determined, based on data obtained from an optical sensor. A per-sub-turn slippage parameter is calculated for each of the plurality of sub-turns, based on any difference between the first parameter and the second parameter. The method further comprises calculating a slippage metric based on the per-sub-turn slippage parameters for the plurality of sub-turns, and causing outputting of a conveyor belt tension adjustment indication.",
  "claims": [
    "1. A method of controlling a printing system, the method comprising: activating a driver to advance a conveyor belt in a plurality of sub-turns, and for each of the plurality of sub-turns: determining a first parameter associated with movement of the conveyor belt based on data obtained from the driver; determining a second parameter associated with movement of the conveyor belt based on data obtained from an optical sensor; and calculating a per-sub-turn slippage parameter based on any difference between the first parameter and the second parameter, the method further comprising: calculating a slippage metric based on the per-sub-turn slippage parameters for the plurality of sub-turns; and causing outputting of a conveyor belt tension adjustment indication.",
    "2. The method of claim 1, wherein for each of the plurality of sub-turns: determining the first parameter comprises determining a first distance travelled by the conveyor belt during the respective sub-turn, based on data obtained from the driver; and determining the second parameter comprises determining a second distance travelled by the conveyor belt during the respective sub-turn, based on data obtained from the optical sensor.",
    "3. The method of claim 1, wherein for each of the plurality of sub-turns: determining the first parameter comprises determining a first linear velocity of the conveyor belt during the respective sub-turn, based on data obtained from the driver; and determining the second parameter comprises determining a second linear velocity of the conveyor belt during the respective sub-turn based on data obtained from the optical sensor.",
    "4. The method of claim 1, wherein calculating the slippage metric comprises aggregating the per-sub-turn slippage parameters for the plurality of sub-turns.",
    "5. The method of claim 1, wherein calculating the slippage metric comprises: for each of the plurality of sub-turns, comparing the per-sub-turn slippage parameter to a predetermined threshold; and calculating a proportion of the plurality of sub-turns where the predetermined threshold is exceeded.",
    "6. The method of claim 1, comprising comparing the slippage metric to a predetermined threshold, and wherein outputting of the conveyor belt tension adjustment indication is caused if the predetermined threshold is exceeded.",
    "7. A non-transitory computer-readable storage medium storing instructions that, if executed by a processor of a printing system, cause the processor to: receive first data relating to a plurality of motions of a driver coupled to a conveyor belt; receive second data relating to optical detection of movement of the conveyor belt; for each of the plurality of driver motions, calculate a per-motion slippage parameter based on any discrepancy between the received first and second data; calculate a slippage metric based on the per-motion slippage parameters; and cause transmittal of a slippage alert signal based on a comparison of the calculated slippage metric to a predetermined threshold value.",
    "8. The non-transitory computer-readable storage medium of claim 7, wherein calculating the per-motion slippage parameter comprises, for each of the plurality of motions of the driver: determining a first distance travelled by the conveyor belt based on the first data; determining a second distance travelled by the conveyor belt based on the second data; and calculating a difference between the first distance and the second distance.",
    "9. The non-transitory computer-readable storage medium of claim 7, wherein calculating the per-motion slippage parameter comprises, for each of the plurality of motions of the driver: determining a first linear velocity of the conveyor belt based on the first data; determining a second linear velocity of the conveyor belt based on the second data; and calculating a difference between the first linear velocity and the second linear velocity.",
    "10. The non-transitory computer-readable storage medium of claim 7, wherein calculating the slippage metric comprises aggregating the per-motion slippage parameters for the plurality of motions of the driver.",
    "11. The non-transitory computer-readable storage medium of claim 7, wherein calculating the slippage metric comprises: for each of the plurality of motions of the driver, comparing the per-motion slippage parameter to a predetermined threshold; and calculating a proportion of the plurality of motions where the predetermined threshold is exceeded.",
    "12. A printing system comprising: a driver to advance a conveyor belt in a plurality of intervals, wherein each of the plurality of intervals comprises a sub-turn of the conveyor belt; an optical sensor to optically detect movement of the conveyor belt; and a diagnostic module to: determine a first parameter associated with movement of the conveyor belt based on data from the driver; determine a second parameter associated with movement of the conveyor belt based on data from the optical sensor; for each of the plurality of intervals, calculate a per-interval slippage parameter based on a difference between the first parameter and the second parameter; calculate a slippage metric based on the per-interval slippage parameters for the plurality of intervals; and based on a comparison of the slippage metric to a predetermined threshold value, cause a conveyor belt tension adjustment indication.",
    "13. The printing system of claim 12, wherein the diagnostic module is to calculate the slippage metric by aggregating the per-interval slippage parameters for the plurality of motions of the driver.",
    "14. The printing system of claim 12, wherein the diagnostic module is to calculate the slippage metric by, for each of the plurality of intervals of the driver, comparing the per-interval slippage parameter to a predetermined threshold and calculating a proportion of the plurality of intervals where the predetermined threshold is exceeded.",
    "15. The printing system of claim 12, wherein the first parameter and the second parameter are each a distance travelled by the conveyor belt in the respective interval of the driver."
  ],
  "description_excerpt": "Conveyor belts for printers may be arranged to move print media in a printing system in coordination with printing components to produce a printed image or generate an object. The conveyor belt supports and moves the print media during printing. The conveyor belt may be positioned around rollers in an assembly which may include a driving mechanism to apply a force to the conveyor belt to cause it to move on the rollers.\n\nVarious features of the present disclosure will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate certain examples, and wherein:\n\nFIG. 1 is a schematic illustration showing a printing system according to an example;\n\nFIG. 2 is a schematic illustration showing corresponding cross sectional views of a conveyor belt for a printing system according to an example;\n\nFIG. 3 is a flow diagram showing a method of controlling a printing system according to an example; and\n\nFIG. 4 is a schematic illustration showing a non-transitory computer-readable storage medium, coupled to a processor, and comprising instructions according to an example.\n\nCertain examples described herein relate to printing systems with a conveyor belt to convey print media. In some examples, the printing system may be a two-dimensional (2D) printing system such as an inkjet or digital offset printer. In these examples, the print media may comprise paper, cardstock, boards, metal sheets, plastic sheets, and the like. A sheet of print media may rest on top of the conveyor belt and be driven through a print zone.",
  "cpc": [
    "B41J 11/007",
    "B41J 11/42",
    "B65G 2203/0291",
    "B65G 2203/044",
    "B65G 23/44",
    "B65G 43/04"
  ],
  "ipc": [
    "B41J 11/00",
    "B41J 11/42",
    "B65G 23/44",
    "B65G 43/04"
  ],
  "assignees": [
    "Hewlett Packard Development Co LP"
  ],
  "inventors": [
    "Roger Terradellas Callau",
    "Inaki Zudaire Rovira",
    "Daniel Gutierrez Garcia"
  ],
  "filing_date": "2017-06-12",
  "publication_date": "2022-01-11",
  "grant_date": "2022-01-11",
  "priority_date": "2017-06-12",
  "application_number": "US-201716493212-A",
  "family_id": "64660156",
  "cited_by_count": 2,
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}