News Column

Patent Issued for Optical Module and Spectroscopic Analyzer

August 13, 2014



By a News Reporter-Staff News Editor at Journal of Engineering -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventor Nozawa, Takeshi (Suwa, JP), filed on January 25, 2012, was published online on July 29, 2014.

The patent's assignee for patent number 8792101 is Seiko Epson Corporation (JP).

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates to an optical module including an interference filter that extracts light of a prescribed wavelength from an incident light and a spectroscopic analyzer including the optical module.

"In the related art, an interference filter (etalon) in which multi-layer films (reflecting films) are disposed on the facing surfaces of a pair of substrates so as to face each other with a prescribed gap therebetween is known (for example, see JP-A-11-142752).

"In the interference filter disclosed in JP-A-11-142752, driving electrodes are disposed on the facing surfaces of the pair of reflecting films so as to face each other in order to adjust the gap, and the gap can be adjusted by an electrostatic attractive force by applying a driving voltage to the respective driving electrodes. In this way, the interference filter can pass only light of a specific wavelength corresponding to the gap. That is, the interference filter causes the incident light to experience multiple interference between the pair of reflecting films and passes only light of the specific wavelength which is strengthened by the multiple interference.

"However, the above-described interference filter is generally used by being incorporated into an optical module or a spectroscopic analyzer. FIG. 13 is a schematic view showing a simplified configuration of a colorimetric device 10 (spectroscopic analyzer) of the related art including an etalon 50.

"The colorimetric device 10 includes a light source device 20 that emits light to a test subject A, the etalon 50 that disperses a test subject light reflected by the test subject A, a light receiving element 420 that receives light having passed through the etalon 50, and a colorimetric sensor 40 (optical module) including an outer housing 40A in which a printed substrate 410 connected to the light source device 20 and the light receiving element 420 is accommodated.

"The colorimetric sensor 40 includes a cylindrical holding housing 310 that is provided adjacent to the light source device 20 so as to hold the outer circumference of the etalon 50.

"Moreover, in the colorimetric device 10, light emitted from the light source device 20 is reflected by the test subject A, and the reflected test subject light is dispersed by the colorimetric sensor 40. Based on a detection signal output from the colorimetric sensor 40, the chromaticity of the test subject light, namely the color of the test subject A is analyzed and measured from the intensities of light of the dispersed respective wavelengths.

"However, in the configuration of the related art shown in FIG. 13, the holding housing 310 holds the outer circumference adjacent to a portion of the etalon 50 in which the reflecting film is formed. In such a configuration, heat generated by the light source device 20 may be transmitted directly to the etalon 50 from the holding housing 310. Thus, the substrate may be deformed by thermal expansion.

"In addition, since the outer circumference of the etalon 50 adjacent to the reflecting film is held by the holding housing 310, the substrate may be deformed by the holding force of the holding housing 310.

"As above, when the reflecting film is deformed, there is a problem in that the transmission wavelength of light passing through the etalon 50 may fluctuate, and the resolution may decrease."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventor's summary information for this patent: "An advantage of some aspects of the invention is that it provides an optical module and a spectroscopic analyzer capable of suppressing a decrease in the resolution of an interference filter.

"An aspect of the invention is directed to an optical module including: an interference filter including a first substrate, a second substrate facing the first substrate, a first reflecting film formed on a surface of the first substrate facing the second substrate, and a second reflecting film formed on the second substrate so as to face the first reflecting film with a prescribed gap therebetween; and a holding member that holds the interference filter, wherein the interference filter includes a light interference area in which the first and second reflecting films are formed in a plan view as seen in a thickness direction of the substrate, and a protruding area protruding in a direction away from the light interference area, and wherein the holding member holds the interference filter at one end side of the protruding area opposite to the light interference area.

"According to the above aspect of the invention, the interference filter includes the light interference area facing the first and second substrates and the protruding area protruding from the light interference area. Moreover, the holding member holds the distal end side (a side opposite to the light interference area) of the protruding area to thereby hold the interference filter. Thus, since the interference filter is held by the holding member at a position away from the reflecting film, the reflecting film formed on the light interference area is not deformed by the holding force of the holding member. Moreover, for example, even when the holding member is heated by a light source device or the like, transmission of heat is suppressed by the protruding area. Therefore, it is possible to suppress heating of the light interference area and to suppress deformation of the substrate and the reflecting film due to heating. Accordingly, since deformation of the reflecting film can be prevented, it is possible to maintain the parallel state between the reflecting films of the interference filter and to suppress a decrease in the resolution.

"In the optical module of the above aspect of the invention, it is preferable that the first and second substrates have the same shape, the interference filter includes a supporting substrate which is bonded to either the first substrate or the second substrate, and the protruding area is formed on the supporting substrate.

"According to the above configuration, the interference filter includes the supporting substrate including the protruding area in addition to the first and second substrates forming the reflecting film. Moreover, since the holding member holds the protruding area of the supporting substrate, the first and second substrates for holding the interference filter are held without being deformed. Moreover, for example, even when heat is transmitted to the holding member, it is possible to suppress heat from being transmitted to the protruding area. Furthermore, since the first and second substrates in which the light interference area is formed are provided to be separate from the supporting member, it is possible to suppress transmission of heat more reliably.

"In the optical module of the above aspect of the invention, the protruding area may be formed on at least one of the first substrate and the second substrate.

"In the above configuration, the protruding area is formed in at least one of the first and second substrates. In such a configuration, since it is not necessary to provide a supporting substrate which is a separate member for forming the protruding area, it is possible to further simplify the configuration.

"In the optical module according to the above aspect of the invention, it is preferable that a vibration absorbing portion that absorbs vibration is formed in the protruding area.

"Here, as the vibration absorbing portion, for example, a portion having a smaller width or thickness dimension than the other portions may be formed in a part of the protruding area so that a structurally weaker portion than the other portions is formed.

"According to the above configuration, since the vibration absorbing portion is formed in the protruding area, when vibration is applied from the outside, the vibration is absorbed by the vibration absorbing portion. Thus, it is possible to suppress the vibration from being transmitted to the light interference area of the interference filter. Therefore, it is possible to prevent a change in the gap between the reflecting films of the interference filter due to vibration applied from the outside.

"Another aspect of the invention is directed to a spectroscopic analyzer including the optical module according to the above aspect, in which the optical module includes a light receiving unit that receives a test subject light extracted by the interference filter, and the spectroscopic analyzer further includes an analysis processing unit that analyzes optical properties of the test subject light based on the intensity of the test subject light received by the light receiving unit.

"According to the above aspect, since the spectroscopic analyzer includes the optical module of the above aspect, it is possible to suppress a decrease in the resolution. Thus, the light receiving unit can measure the light intensity with high accuracy. Moreover, by performing spectroscopic analysis based on the measurement results, it is possible to obtain accurate spectroscopic properties."

For additional information on this patent, see: Nozawa, Takeshi. Optical Module and Spectroscopic Analyzer. U.S. Patent Number 8792101, filed January 25, 2012, and published online on July 29, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8792101.PN.&OS=PN/8792101RS=PN/8792101

Keywords for this news article include: Seiko Epson Corporation.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Journal of Engineering


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters