Title:
【発明の名称】光学的ロ―パスフィルタ
Document Type and Number:
Japanese Patent JP2507041
Kind Code:
B2
Abstract:
PURPOSE:To reduce the size and cost of the optical low-pass filter without deteriorating the performance thereof by laminating and disposing 1st and 2nd double refractive plates which separate an ordinary light component and an extraordinary light component at respectively different angles and distances. CONSTITUTION:The 1st double refractive plate 11 which separates the ordinary light component and the extraordinary light component at a distance d1 at about 45 deg. angle with the horizontal scanning direction of a solid-state image pickup element and the 2nd double refractive plate 12 which separates the ordinary light component and the extraordinary light component at a distance d2 approximately parallel with the horizontal scanning direction are laminated and disposed. The values approximate to ideal characteristics in the frequency characteristics of not only the horizontal direction but the perpendicular direction as well are, therefore, attained even if the value Py/Px of the relation between the horizontal inter-picture element spacing Px and perpendicular inter-picture element spacing Py of the solid-state image pickup element is different as largely as 1/2. The optical low-pass filter of the performance equal to or better than the performance of the conventional method is obtd. with the smaller number of constituting elements. The smaller size, the lower cost and the higher performance are thus obtd.
Inventors:
NAKAYAMA MASAAKI
Application Number:
JP10933089A
Publication Date:
June 12, 1996
Filing Date:
April 28, 1989
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
G02B27/28; G02B27/46; H04N5/335; H04N5/357; H04N5/372; (IPC1-7): G02B27/46; H04N5/335
Domestic Patent References:
| JP619617A | ||||
| JP5975222A | ||||
| JP6241122U |
Attorney, Agent or Firm:
Tomoyuki Takimoto