Title:
OPTICAL FILTER AND IMAGING OPTICAL SYSTEM
Document Type and Number:
Japanese Patent JP2018092030
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide an optical filter having a function of stably adjusting light quantity, and an image pickup device.SOLUTION: A light quantity adjustment layer provided on at least one surface of a light permeable substrate is composed of first and second light absorption layers and a multilayer-structured intermediate layer formed between the first and second light absorption layers. A visible light wavelength region of a layer of the multilayer-structured intermediate layer close to the first light absorption layer has an extinction coefficient greater than that of a visible light wavelength region of a layer close to the second light absorption layer. The layer close to the first light absorption layer has a film thickness greater than that of the layer close to the second light absorption layer.SELECTED DRAWING: Figure 1
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Inventors:
SATO YASUHIRO
Application Number:
JP2016235944A
Publication Date:
June 14, 2018
Filing Date:
December 05, 2016
Export Citation:
Assignee:
CANON DENSHI KK
International Classes:
G02B5/00; C23C14/06; G02B5/26; G02B5/28; G03B11/00
Domestic Patent References:
| JP2016194110A | 2016-11-17 | |||
| JP2011100042A | 2011-05-19 | |||
| JP2007225735A | 2007-09-06 | |||
| JP2011081083A | 2011-04-21 | |||
| JP2012159815A | 2012-08-23 | |||
| JP2005326687A | 2005-11-24 | |||
| JP2011118251A | 2011-06-16 |
Foreign References:
| US4960310A | 1990-10-02 | |||
| CN104297833A | 2015-01-21 |