Printing apparatus

{
  "publication_number": "US9764549B2",
  "country": "US",
  "kind": "B2",
  "title": "Printing apparatus",
  "abstract": "A printing apparatus including a discharge head that performs scanning movement with respect to a print medium and discharges ink to a surface of the print medium, a signal output unit which includes a reference scale in which optical density changes stepwise along a scanning movement direction of the discharge head and a reading unit that optically reads the reference scale and outputs a signal according to the optical density and in which the reference scale and the reading unit move relatively with each other along with the movement of the discharge head, and a stain detection unit that detects stain of the signal output unit based on a detection result of a strength level of the signal.",
  "claims": [
    "1. A printing apparatus comprising: a discharge head that performs scanning movement with respect to a print medium and discharges ink to a surface of the print medium; a signal output unit including a reference scale in which optical density changes stepwise along a scanning movement direction of the discharge head and a reading unit that optically reads the reference scale and outputs a signal according to the optical density, the reference scale and the reading unit moving relatively with each other along with the movement of the discharge head; a stain detection unit that detects stain of the signal output unit based on a detection result of a strength level of the signal; and a signal history holding unit that holds information related to a history of change in the strength level of the signal.",
    "2. The printing apparatus according to claim 1, wherein the stain detection unit detects the strength level of the signal by converting the signal into a multi-valued data of three values or more.",
    "3. The printing apparatus according to claim 1, further comprising: a setting history holding unit that holds information related to a history of a print setting; and an evaluation unit that evaluates a correlation between the print setting and the stain based on the information held by the signal history holding unit and the information held by the setting history holding unit.",
    "4. The printing apparatus according to claim 3, further comprising: a notification unit that notifies a user of a print setting that is evaluated to be highly correlated with the stain by the evaluation unit.",
    "5. The printing apparatus according to claim 4, wherein the notification unit notifies a user of a print setting whose correlation with the stain is lower than that of the current print setting.",
    "6. The printing apparatus according to claim 3, further comprising: an estimation unit that estimates a service life of the signal output unit in printing based on one print setting, based on an evaluation result of the evaluation unit.",
    "7. The printing apparatus according to claim 3, wherein the setting history holding unit integrates an operation amount of the discharge head under a print setting for each print setting.",
    "8. The printing apparatus according to claim 3, further comprising: a displacement detection unit that detects a displacement of the discharge head based on a detection result of a variation timing of the signal during a period in which the discharge head performs scanning movement, wherein the setting history holding unit holds the number of times of occurrence of detection error of the displacement in the displacement detection unit for each print setting.",
    "9. The printing apparatus according to claim 3, further comprising: a support unit that supports the print medium to face the discharge head, wherein a setting of a gap between the support unit and the discharge head can be changed, and the information held by the setting history holding unit includes information related to the gap between the support unit and the discharge head."
  ],
  "description_excerpt": "1. Technical Field\n\nThe present invention relates to a printing apparatus that performs printing on a print medium by causing a discharge head to perform scanning movement and, in particular to, a technique that optically detects displacement of a discharge head.\n\n2. Related Art\n\nFor example, in a printing apparatus such as an ink jet printer that performs printing on a print medium by discharging ink from a discharge head that performs scanning movement with respect to the print medium, an optical detection means may be used to detect displacement of the discharge head. For example, in a technique described in JP-A-2010-188532 (for example, FIG. 3), a displacement of a carriage is detected by a linear encoder in which a scale fixed to a printing apparatus and an optical sensor attached to a carriage are combined. In such a printing apparatus, there is a problem that a detection sensitivity of position or displacement gradually degrades due to adhesion of ink mist flying from a discharge head.\n\nFor this problem, the technique described in JP-A-2010-188532 estimates a timing at which the service life of an encoder expires by associating an occurrence frequency of false detection with an integrated amount of used ink and notifies a user of the service life and/or sends warning to a user as needed.\n\nA use mode of the printing apparatus as described above varies depending on each user, so that the service life estimation described above may not function appropriately in some cases.",
  "cpc": [
    "B41J 2/04586",
    "B41J 11/0095",
    "B41J 19/207",
    "B41J 2/125",
    "B41J 29/38",
    "B41J 3/4078"
  ],
  "ipc": [
    "B41J 2/02",
    "B41J 25/304",
    "B41J 2/045",
    "B41J 2/125",
    "B41J 11/00",
    "B41J 19/20",
    "B41J 3/407"
  ],
  "assignees": [
    "Seiko Epson Corp"
  ],
  "inventors": [
    "Yoshiyuki Kimoto"
  ],
  "filing_date": "2016-06-10",
  "publication_date": "2017-09-19",
  "grant_date": "2017-09-19",
  "priority_date": "2015-06-29",
  "application_number": "US-201615179564-A",
  "family_id": "57601484",
  "cited_by_count": 5,
  "citations": [
    "JP2005231155A",
    "US7731330B2",
    "US8177320B2",
    "JP5338476B2",
    "US20100165022A1",
    "JP2010188532A"
  ]
}