An Absolute Optical Encoder using Modulated-Photo-Diode Arrays

Atsushi Ieki, Kazuhiro Hane, Masafumi Yokoyama, Keiji Matsui, Masayuki Nashiki, Minoru Sasaki

Research output: Contribution to journalArticlepeer-review


In this paper, a compact absolute optical linear encoder is proposed. The index scale of the proposed encoder has the two track (80 μm and 2 mm pitches), which consist of the pitch-modulated grating and slit-width-modulated grating, respectively. Using the modulated gratings, the harmonic noises of the encoder signals are decreased. Moreover, the respective lines of the slit-width-modulated grating are divided and re-distributed in the index scale to suppress the sensing error due to the contamination on the scale. By fabricating the index scale with silicon photodiode arrays, the proposed advantages are confirmed experimentally.

Original languageEnglish
Pages (from-to)364-369
Number of pages6
JournalNihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C
Issue number654
Publication statusPublished - 2001
Externally publishedYes


  • Absolute Detection
  • Modulated Grating
  • Optical Encoder
  • Optical Measurement
  • Photo-Diode Arrays
  • Positioning
  • Sensor

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering


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