Infrared detection element, infrared detector, and infrared type gas sensor

The infrared detection element according to claim 4, wherein the first surface electrode and the second surface electrode have sheet resistances that function as infrared reflection layers for reflecting infrared.

The infrared detection element according to claim 4, wherein the infrared absorption layer is provided so as to cover a whole region that is surrounded by the slit in planar view,nthe infrared absorption layer is formed of a first resin layer in which at least one kind of conductive fine powder is dispersed in resin, and the at least one kind of conductive fine powder is selected from a group of carbon fine powder, metal fine powder and metal oxide fine powder.

The infrared detector according to claim 7, wherein the infrared detection element comprises two sets of the first pyroelectric element for receiving infrared light and the second pyroelectric element for compensating temperature, one set thereof constituting a first detection element, another set thereof constituting a second detection element, and the first detection element and the second detection element being on the single pyroelectric substrate,nthe optical filter comprises:na first optical filter disposed in front of a light receiving surface of the first pyroelectric element of the first detection element; anda second optical filter disposed in front of a light receiving surface of the first pyroelectric element of the second detection element,the first detection element and the second detection element respectively comprise first output terminals provided on the surface of the single pyroelectric substrate, the first detection element and the second detection element further respectively comprising second output terminals provided on the back face of the single pyroelectric substrate,the first output terminals are disposed so as not to overlap with the second output terminals in a thickness direction of the single pyroelectric substrate,the base body comprises:nan insulation base member having an electric insulation property;two first lead terminals; andtwo second lead terminals, the two first lead terminals and the two first lead terminals being provided integrally with the insulation base member,the first lead terminals are respectively electrically connected with the first output terminals of the first detection element and the second detection element individually via first bonding portions, each of which is made of a conductive adhesive,the second lead terminals are respectively electrically connected with the second output terminals of the first detection element and the second detection element individually via second bonding portions, each of which is made of a conductive adhesive,the insulation base member is provided on a first surface thereof with at least one of:na projection for positioning the infrared detection element, the projection projecting between each of the first lead terminals and a corresponding second lead terminal, outside an area where the infrared detection element is to be mounted, in a thickness direction of the insulation base member; anda wall for positioning the infrared detection element, the wall projecting, outside the area where the infrared detection element is to be mounted, in the thickness direction of the insulation base member, a height of the wall being smaller than a thickness of the infrared detection element.

The infrared detector according to claim 7, wherein the first pyroelectric element for receiving infrared light and the second pyroelectric element for compensating temperature, which are paired, of the infrared detection element are arranged on the single pyroelectric substrate,nthe first pyroelectric element and the second pyroelectric element,which are paired, are connected in reverse parallel to or in reverse series to each other,the infrared detection element is disposed such that the first pyroelectric element is positioned in an area of the infrared detection element, which is a vertically projected area from the window hole,the optical filter is disposed between the window member and the first pyroelectric element, andthe infrared detector further comprises a light blocking member that is disposed between the window member and the infrared detection element,the light blocking member being configured to block infrared that is directed toward the second pyroelectric element, after passing through the window member from an outside of the package and entering the package,and the light blocking member being held by the base body.

An infrared type gas sensor comprising the infrared detector according to claim 7, and an infrared emitting element configured to emit infrared by thermal radiation,nwherein the infrared detector further comprises an IC element for signal processing an output signal of the infrared detection element, andthe infrared type gas sensor further comprises:na sample cell disposed between the infrared emitting element and the infrared detector, the sample cell allowing gas as a detection object to introduce therein or to discharge outside;a drive circuit configured to intermittently energize the infrared emitting element;a controller configured to control the drive circuit; anda signal processing circuit configured to signal-process an output signal of the IC element to calculate concentration of the gas as the detection object.

The infrared type gas sensor according to claim 15, comprising a first light receiving element and a second light receiving element,nwherein the infrared detection element is formed with two sets of the first pyroelectric element for receiving infrared light and the second pyroelectric element for compensating temperature, one set thereof constituting a first detection element,another set thereof constituting a second detection element and the first detection element and the second detection element being on the single pyroelectric substrate,the first pyroelectric element of the first detection element constitutes the first light receiving element,the first pyroelectric element of the second detection element constitutes the second light receiving element, the infrared type gas sensor further comprises:a first optical system disposed between the infrared emitting element and the first light receiving element;a second optical system disposed between the infrared emitting element and the second light receiving element;a drive circuit configured to drive the infrared emitting element; anda signal processor configured to calculate concentration of gas as a detection object based on a ratio between a first output signal of the first light receiving element and a second output signal of the second light receiving element,the first optical system has a first transmission wavelength band for transmitting infrared having an absorption wavelength of the gas as the detection object,the second optical system has a second transmission wavelength band for transmitting infrared having a reference wavelength,the first transmission wavelength band is different from the second transmission wavelength band,all wavelengths in the second transmission wavelength band are shorter than all wavelengths in the first transmission wavelength band the first optical system and the second optical system have a common prescribed wavelength band for compensation, all wavelengths in the common prescribed wavelength band are longer than all wavelengths in the first and second transmission wavelength bands, the first optical system has a first average transmittance in the common prescribed wavelength band, which is less than a second average transmittance of the second optical system in the common prescribed wavelength band and the first and second average transmittances are set to compensate a change in a ratio between: a first output signal component of the first light receiving element based on infrared having the first transmission wavelength band; and a second output signal component of the second light receiving element based on infrared having the second transmission wavelength band, the change in the ratio being caused due to a change in emission power of the infrared emitting element.

The infrared type gas sensor according to claim 15, comprising a first light receiving element and a second light receiving element,nwherein the infrared detection element is formed with two sets of the first pyroelectric element for receiving infrared light and the second pyroelectric element for compensating temperature, one set thereof constituting a first detection element,another set thereof constituting a second detection element, and the first detection element and the second detection element being on the single pyroelectric substrate,the first pyroelectric element of the first detection element constitutes the first light receiving element,the first pyroelectric element of the second detection element constitutes the second light receiving element, the infrared type gas sensor further comprises:a first optical system disposed between the infrared emitting element and the first light receiving element;a second optical system disposed between the infrared emitting element and the second light receiving element;a drive circuit configured to drive the infrared emitting element; anda signal processor configured to calculate concentration of gas as a detection object based on a ratio between a first output signal of the first light receiving element and a second output signal of the second light receiving element,the first optical system has a first transmission wavelength band for transmitting infrared having an absorption wavelength of the gas as the detection object,the second optical system has a second transmission wavelength band for transmitting infrared having a reference wavelength,the first transmission wavelength band is different from the second transmission wavelength band,all wavelengths in the second transmission wavelength band are longer than all wavelengths in the first transmission wavelength band,the first optical system and the second optical system have a common prescribed wavelength band for compensation,all wavelengths in the common prescribed wavelength band are longer than all wavelengths in the first and second transmission wavelength bands,the first optical system has a first average transmittance in the common prescribed wavelength band which is more than a second average transmittance of the second optical system in the common prescribed wavelength band, andthe first and second average transmittances are set to compensate a change in a ratio between:a first output signal component of the first light receiving element based on infrared having the first transmission wavelength band; anda second output signal component of the second light receiving element based on infrared having the second transmission wavelength band,the change in the ratio being caused due to a change in emission power of the infrared emitting element.

The infrared type gas sensor according to claim 15, further comprising:nan optical system disposed between the infrared emitting element and the infrared detection element,the optical system having respective infrared transmittances in a first transmission wavelength band for transmitting infrared having an absorption wavelength of gas as a detection object, and a second transmission wavelength band,all wavelengths in the second transmission wavelength band being longer than all wavelengths in the first transmission wavelength band,the second transmission wavelength band having an average transmittance that is less than that of the first transmission wavelength band;a drive circuit configured to pulse-drive the infrared emitting element;a controller configured to control the drive circuit in time series such that the drive circuit pulse-drives the infrared emitting element under a first drive condition or a second drive condition,the infrared emitting element under the first drive condition having a peak wavelength in an emission energy distribution that is different from that under the second drive condition; anda signal processor configured to estimate concentration of gas as a detection object based on a ratio between a first output signal of the infrared detection element under the first drive condition and a second output signal of the infrared detection element under the second drive condition.