JP6477058B2 - Infrared sensor - Google Patents

Description

  The present invention relates to an infrared sensor that detects infrared rays from a measurement object and measures the temperature of the measurement object.

In general, in order to measure the temperature of an object to be measured such as a fixing roller used in an image forming apparatus such as a copying machine or a printer, an infrared sensor is disposed opposite the object to be measured and receives the radiant heat to measure the temperature. Is installed.
For example, in Patent Document 1, a resin film installed on a holder, a thermal element for detecting infrared rays that is provided on the resin film and detects infrared rays through a light guide portion of the holder, and provided in a light-shielded state on the resin film. An infrared temperature sensor including a temperature-compensating thermosensitive element for detecting the temperature of the holder is proposed.

  On the other hand, as other infrared sensors, for example, in Patent Documents 2 and 3, an insulating film, and a first thermal element and a second thermal element provided on one surface of the insulating film so as to be separated from each other. A conductive first wiring film formed on one surface of the insulating film and connected to the first thermal element; a conductive second wiring film connected to the second thermal element; An infrared sensor including an infrared reflection film provided on the other surface of the insulating film so as to face the two thermal elements has been proposed.

JP 2002-156284 A JP 2012-225893 A JP 2012-212789 A

The following problems remain in the conventional technology.
In the fixing roller of the image forming apparatus, temperature distribution occurs in the fixing roller depending on the size of the paper to be printed (for example, the size of A4 or A3). Therefore, it is necessary to measure two areas in the axial direction of the fixing roller. Therefore, conventionally, as shown in FIG. 7, the two infrared sensors 101A and 101B are arranged opposite to the fixing roller R to measure two regions. However, in the case of this conventional measurement method, it is necessary to install the two infrared sensors 101A and 101B sufficiently apart from each other in order to prevent the fields of view of the two infrared sensors 101A and 101B from overlapping and the measurement area from overlapping. Yes, the space for installing the two infrared sensors 101A and 101B had to be set wide. Further, it is necessary to install the two infrared sensors 101A and 101B, and there is a disadvantage that the number of parts increases.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an infrared sensor capable of separately measuring the temperatures of two measurement regions.

  The present invention employs the following configuration in order to solve the above problems. That is, the infrared sensor according to the first invention includes a substrate, a first sensor unit and a second sensor unit which are heat-sensitive units provided on the upper surface of the substrate and spaced apart from each other, and the first sensor unit. And a cylindrical light guide section that has an opening above the second sensor section and covers the periphery of the heat-sensitive surface of the first sensor section and the second sensor section, and the light guide section Are an outer wall part surrounding the first sensor part and the second sensor part, an opening part provided in the outer wall part and above the first sensor part, and an upper part of the second sensor part. And a partition plate portion higher than the outer wall portion.

  In this infrared sensor, the light guide path portion includes an outer wall portion surrounding the first sensor portion and the second sensor portion, an opening portion provided in the outer wall portion and above the first sensor portion, and the second sensor. Since the upper partition portion is partitioned and the partition plate portion higher than the outer wall portion, the high partition plate portion overlaps the first sensor portion and the second sensor portion. The overlap of measurement areas can be reduced by blocking. Thus, the distance between the first sensor unit and the second sensor unit is shortened by integrating the two sensor units and providing the partition plate unit so that the visual fields of the two sensor units do not overlap as much as possible. It can be set and the whole can be reduced in size. Therefore, in the infrared sensor of the present invention, it is possible to measure two measurement areas separately with high accuracy, and it is possible to install in a smaller space than in the past.

An infrared sensor according to a second aspect of the invention is characterized in that, in the first aspect of the invention, a third sensor part which is a heat sensitive part is provided immediately below the partition plate part on the upper surface of the substrate.
That is, in this infrared sensor, since the third sensor part which is a heat sensitive part is provided immediately below the partition plate part on the upper surface of the substrate, the infrared ray is incident by the third sensor part being behind the partition plate part. Is prevented, and a sensor unit for compensation can be obtained.

An infrared sensor according to a third invention is the infrared sensor according to the first or second invention, wherein the front end portion of the partition plate portion is formed wide on the first sensor portion side and the second sensor portion side. It is characterized by that.
That is, in this infrared sensor, since the tip end portion of the partition plate portion is formed wide on the first sensor portion side and the second sensor portion side, the height of the partition plate portion need not be set higher. Also, the overlap of the visual fields of the first sensor portion and the second sensor portion can be set narrower by the wide tip portion.

An infrared sensor according to a fourth invention is the infrared sensor according to the second invention, comprising an insulating film installed directly on the upper surface of the substrate or via another member, wherein the first sensor portion is the insulating film. A first thermosensitive element provided on one surface on the substrate side, and a conductive first wiring film formed on one surface of the insulating film and connected to the first thermosensitive element; And the second sensor part is formed on one surface of the insulating film, the second heat sensitive element provided on one surface of the insulating film and spaced from the first heat sensitive element. And a conductive second wiring film connected to the second thermosensitive element, wherein the third sensor portion is provided on one surface of the insulating film and immediately below the partition plate portion. A third heat sensitive element formed on one surface of the insulating film A conductive third wiring film formed and connected to the third thermal element; and an infrared reflecting film provided on the other surface of the insulating film so as to face the third thermal element. The infrared reflection film and the partition plate portion are arranged with a gap therebetween.
That is, in this infrared sensor, since the infrared reflecting film and the partition plate portion are arranged with a gap, it is possible to prevent the heat from being transmitted from the partition plate portion and escape, and particularly for compensation. The accuracy of the third sensor unit can be improved.

An infrared sensor according to a fifth invention is the infrared sensor according to the fourth invention, wherein the insulating film is between the first sensor part and the third sensor part and between the second sensor part and the third sensor part. It has a pair of slits formed between each sensor part.
That is, in this infrared sensor, the insulating film has a pair of slits formed between the first sensor unit and the third sensor unit and between the second sensor unit and the third sensor unit, respectively. Since it has, it can prevent with a slit that heat is transmitted between the 3rd sensor part used as compensation, and the 1st sensor part and the 2nd sensor part of both sides.

The present invention has the following effects.
That is, according to the infrared sensor according to the present invention, the light guide path portion includes the outer wall portion surrounding the first sensor portion and the second sensor portion, and the upper wall portion provided in the outer wall portion and above the first sensor portion. Since the opening and the opening above the second sensor part are partitioned and the partition plate part is higher than the outer wall part, the high partition plate part includes the first sensor part and the second sensor part. The overlapping of the measurement areas can be reduced by blocking the overlapping viewing angle portions. Therefore, when measuring the temperature of the two measurement areas of the fixing roller, conventionally, it was necessary to attach two infrared sensors, whereas in the infrared sensor of the present invention, only one of the two measurement areas is required. The temperature can be measured with high accuracy, and the number of members and the member cost can be reduced.

It is sectional drawing which shows 1st Embodiment of the infrared sensor which concerns on this invention. In 1st Embodiment, it is a perspective view which shows a light guide path part. In 1st Embodiment, it is a figure which shows the other surface (a) and one surface (b) of the insulating film in which the 1st to 3rd sensor part was provided. FIG. 3 is an explanatory diagram illustrating a state in which an infrared sensor is disposed to face a fixing roller in the first embodiment. It is sectional drawing which shows 2nd Embodiment of the infrared sensor which concerns on this invention. In 3rd Embodiment of the infrared sensor which concerns on this invention, it is a figure which shows the other surface (a) of the insulating film in which the 1st to 3rd sensor part was provided, and one surface (b). FIG. 7 is an explanatory diagram showing a state in which two infrared sensors are arranged to face a fixing roller in a conventional example of an infrared sensor according to the present invention.

  Hereinafter, a first embodiment of an infrared sensor according to the present invention will be described with reference to FIGS. 1 to 3. In each drawing used for the following description, the scale is appropriately changed in order to make each member recognizable or easily recognizable.

  As shown in FIGS. 1 to 3, the infrared sensor 1 according to the present embodiment includes a substrate 2, a first sensor unit 3 </ b> A and a second sensor that are heat-sensitive units provided on the upper surface of the substrate 2 so as to be separated from each other. A cylinder having an opening above the first sensor unit 3A and the second sensor unit 3B and covering the periphery of the heat-sensitive surfaces 3a and 3b of the first sensor unit 3A and the second sensor unit 3B The light guide path part 4 is provided. That is, the infrared sensor 1 is a compound eye non-contact temperature sensor having two infrared detection sensor portions 3A and 3B.

The light guide path portion 4 is provided in the outer wall portions 4a and 4b surrounding the first sensor portion 3A and the second sensor portion 3B, and in the outer wall portions 4a and 4b and above the first sensor portion 3A. The opening part and the opening part above 2nd sensor part 3B are partitioned off, and it has the partition plate part 4c higher than outer wall part 4a, 4b. The light guide path portion 4 is formed in a rectangular shape in plan view, and the outer wall portion 4a orthogonal to the longitudinal direction is set lower than the outer wall portion 4b orthogonal to the short direction in order to widen the visual field in the longitudinal direction.
In addition, the light guide part 4 is installed in the upper surface of the board | substrate 2 covering the outer periphery of the housing | casing 5, for example, is comprised with metal plates, such as stainless steel and aluminum.

Furthermore, the infrared sensor 1 of the present embodiment includes a third sensor unit 3C, which is a heat-sensitive unit, directly below the partition plate unit 4c on the upper surface of the substrate 2, and an insulation installed on the upper surface of the substrate 2 via a housing 5. The film 6 is provided.
As shown in FIG. 3, the first sensor portion 3 </ b> A has a first heat sensitive element 7 a provided on one surface on the substrate 2 side of the insulating film 6, and one surface of the insulating film 6. And a conductive first wiring film 8A formed and connected to the first thermal element 7b.
The second sensor portion 3B is formed on one surface of the insulating film 6 and the second heat sensitive element 7b provided on one surface of the insulating film 6 so as to be separated from the first heat sensitive element 7a. And a conductive second wiring film 8B connected to the second thermal element 7b.

The third sensor portion 3C is formed on one surface of the insulating film 6 and a third heat sensitive element 7c provided on one surface of the insulating film 6 directly below the partition plate portion 4c. A conductive third wiring film 8C connected to the third thermal element 7c, and an infrared reflecting film 9 provided on the other surface of the insulating film 6 so as to face the third thermal element 7c. Yes.
That is, the third sensor unit 3C is for temperature compensation, and the first sensor unit 3A and the second sensor unit 3B are for infrared detection.
The infrared reflection film 9 and the partition plate portion 4c are arranged with a gap therebetween. That is, both ends of the partition plate portion 4 c are fixed to the outer wall portions 4 b on both sides thereof, and the lower end portion is not in contact with the lower infrared reflecting film 9.

The substrate 2 is a printed circuit board (PCB), for example, and is formed in a rectangular shape.
The first thermal element 7a, the second thermal element 7b, and the third thermal element 7c are chip thermistors in which terminal electrodes are formed at both ends. As the thermistor, there are thermistors of the NTC type, the PTC type, the CTR type, etc. In this embodiment, as the first thermal element 7a, the second thermal element 7b, and the third thermal element 7c, for example, the NTC type A thermistor is used. This thermistor is formed of a thermistor material such as a Mn—Co—Cu-based material or a Mn—Co—Fe-based material.

In particular, in the present embodiment, as the first thermal element 7a, the second thermal element 7b, and the third thermal element 7c, a ceramic sintered body containing a metal oxide of Mn, Co, and Fe, that is, Mn—Co -Thermistor element made of Fe-based material is used. Furthermore, this ceramic sintered body preferably has a crystal structure having a cubic spinel phase as a main phase. In particular, as a ceramic sintered body, a single-phase crystal structure composed of a cubic spinel phase is most desirable.
The first thermal element 7a, the second thermal element 7b, and the third thermal element 7c are the first wiring film 8A, the second wiring film 8B, or the third wiring film corresponding to each terminal electrode. It is bonded to 8C and mounted on the insulating film 6.

The first wiring film 8A and the second wiring film 8B are formed so as to be arranged around the first thermal element 7a or the second thermal element 7b.
The pair of first wiring films 8A has the first thermal element 7a disposed therebetween, and the pair of second wiring films 8B has the second thermal element 7b disposed therebetween.

  The pair of first wiring films 8A is connected to the first adhesive electrode 8a formed on the insulating film 6 at one end thereof, and the peripheral edge of the insulating film 6 at the other end. The first terminal electrode 10a formed above is connected. The pair of second wiring films 8B are connected to the second adhesive electrodes 8b formed on the insulating film 6 at one end thereof and to the other end portions of the insulating film 6 respectively. A second terminal electrode 10b formed on the peripheral edge is connected. Further, a third adhesive electrode (not shown) formed on the insulating film 6 is connected to one end of each of the pair of third wiring films 8C, and insulative to the other end. A third terminal electrode 10c formed on the peripheral edge of the film 6 is connected.

Note that, between the first adhesive electrode 8a and the first terminal electrode 10a, between the second adhesive electrode 8b and the second terminal electrode 10b, and between the third adhesive electrode and the third terminal electrode 10c. The space is connected by a linear wiring.
Further, the first adhesive electrode 8a, the second adhesive electrode 8b, and the third adhesive electrode respectively include the corresponding first thermal element 7a, second thermal element 7b, and third thermal element 7c. The terminal electrode is bonded with a conductive adhesive such as solder.

  The insulating film 6 is formed of a polyimide resin sheet, and the infrared reflecting film 9, the first wiring film 8A, the second wiring film 8B, and the third wiring film 8C are formed of copper foil. That is, they are floats of copper foil used as the infrared reflecting film 9, the first wiring film 8A, the second wiring film 8B, and the third wiring film 8C on both surfaces of the polyimide substrate used as the insulating film 6. The electrode is made of a double-sided flexible substrate on which a pattern is formed.

Further, as shown in FIG. 3A, the infrared reflection film 9 includes a portion arranged in a rectangular shape immediately above and around the third thermal element 7c, the first sensor unit 3A, and the first sensor unit 3A. It is comprised with the part currently formed in frame shape so that the absorption area (light-receiving area | region) immediately above 2 sensor part 3B may be enclosed. That is, the region surrounded by the frame-shaped infrared reflection film 9 becomes an infrared absorption region (heat-sensitive surfaces 3a and 3b).
The infrared reflecting film 9 is composed of a copper foil and a gold plating film laminated on the copper foil. In addition to the gold plating film, for example, a mirror-deposited aluminum vapor deposition film or an aluminum foil may be used.

The housing 5 is formed in a box shape with a resin such as PPS (polyphenylene sulfide resin), and an insulating film 6 is provided on the upper part to provide a first thermal element 7a, a second thermal element 7b and a third thermal element. The thermal element 7c is housed and surface-mounted on the upper surface of the substrate 2.
The casing 5 has a plurality of side surface electrode portions (shown in the figure) that are provided on the side surface and that have upper ends connected to the first terminal electrode 10a, the second terminal electrode 10b, and the third terminal electrode 10c and that extend to the bottom. And a plurality of mounting external terminals (not shown) that are connected to the lower end of the side electrode portion at the lower side surface and are connected to the wiring on the upper surface of the lower substrate 2.

  As described above, in the infrared sensor 1 of the present embodiment, the light guide path portion 4 is formed in the outer wall portions 4a and 4b and the outer wall portions 4a and 4b surrounding the first sensor portion 3A and the second sensor portion 3B. It is provided and has a partition plate portion 4c that is higher than the outer wall portions 4a and 4b and partitions the upper opening portion of the first sensor portion 3A and the upper opening portion of the second sensor portion 3B. The partition plate portion 4c can block the overlapping viewing angle portions of the first sensor portion 3A and the second sensor portion 3B so as to reduce the overlapping of measurement regions.

  Thus, by integrating the two sensor parts and providing the partition plate part 4c so that the fields of view of the two sensor parts do not overlap as much as possible, the first sensor part 3A and the second sensor part 3B The distance can be set short, and the whole can be miniaturized. Therefore, in the infrared sensor 1 of the present embodiment, two measurement areas can be measured separately with high accuracy, and can be installed in a smaller space than in the past.

In addition, since the third sensor unit 3C, which is a heat sensitive part, is provided immediately below the partition plate portion 4c on the upper surface of the substrate 2, infrared rays are incident by the third sensor unit 3C being behind the partition plate portion 4c. Is prevented, and a sensor unit for compensation can be obtained. In particular, since the infrared reflective film 9 is formed so as to face the third sensor unit 3C, the infrared reflective film 9 reflects infrared rays from the opening, and the partition plate unit 4c and the third sensor unit 3C. Prevents the incidence of infrared rays.
Further, since the infrared reflecting film 9 and the partition plate portion 4c are arranged with a gap therebetween, it is possible to prevent heat from being transmitted from the partition plate portion 4c and escape, and in particular, the third compensation layer. The accuracy of the sensor unit 3C can be improved.

  Next, 2nd and 3rd embodiment of the infrared sensor which concerns on this invention is described below with reference to FIG.5 and FIG.6. Note that, in the following description of the embodiment, the same components described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The difference between the second embodiment and the first embodiment is that, in the first embodiment, the partition plate portion 4c uses only one plate orthogonal to the longitudinal direction of the substrate 2, whereas In the temperature sensor 21 according to the second embodiment, as shown in FIG. 5, a wide plate portion 24 d parallel to the substrate 2 is fixed to the distal end portion of the partition plate portion 24 c. That is, in 2nd Embodiment, the front-end | tip part of the partition plate part 24c in the light-guide path part 24 is formed wide in the 1st sensor part 3A side and the 2nd sensor part 3B side.

The wide plate portion 24d has a width that narrows the visual field inside the first sensor portion 3A and the second sensor portion 3B to a predetermined range, and extends along the partition plate portion 24c. It is a board.
As described above, in the temperature sensor 21 according to the second embodiment, since the front end portion of the partition plate portion 4c is formed wide, even if the height of the partition plate portion 4c is not set higher, the wide end portion (wide) With the plate portion 24d), the inner visual fields of the first sensor portion 3A and the second sensor portion 3B can be set narrower.

  Next, the difference between the third embodiment and the first embodiment is that in the first embodiment, the insulating film 6 has no holes, but in the second embodiment, as shown in FIG. The film 36 has a pair of slits 36a formed between the first sensor unit 3A and the third sensor unit 3C and between the second sensor unit 3B and the third sensor unit 3C. It is a point. That is, in the third embodiment, slits 36 a that are elongated through holes extending along both sides of the central infrared reflection film 9 are formed in the insulating film 36.

  Thus, in 3rd Embodiment, the insulating film 36 is respectively between the 1st sensor part 3A and the 3rd sensor part 3C, and between the 2nd sensor part 3B and the 3rd sensor part 3C. Since it has a pair of formed slits 36a, it is considered that heat is transferred between the third sensor part 3C for compensation and the first sensor part 3A and the second sensor part 3B on both sides. It can be blocked at 36a. Therefore, temperature compensation by the third sensor unit 3C can be performed more accurately, and temperature detection can be performed with high accuracy.

  The technical scope of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the said embodiment, although the 1st thermal element and the 2nd thermal element detect the heat | fever conducted from the insulating film which absorbed infrared rays directly, the 1st thermal element and the 2nd thermal element An infrared absorption film may be formed on the insulating film immediately above. In this case, the infrared absorption effect in the first thermal element and the second thermal element is further improved, and the first thermal element for infrared detection, the second thermal element, and the third thermal element for compensation. A better temperature difference can be obtained. That is, the infrared ray absorbing film absorbs infrared rays due to radiation from the object to be measured, and the first heat sensitive element and the first layer directly below the infrared ray absorbing film that has absorbed infrared rays and generated heat through the insulating film. The temperature of the thermosensitive element 2 may be changed.

Further, although the first to third thermal elements of the chip thermistor are employed, the first to third thermal elements formed of a thin film thermistor may be employed.
As the thermal element, a thin film thermistor or a chip thermistor is used as described above, but a pyroelectric element or the like can be used in addition to the thermistor.

Moreover, in the housing | casing of said each embodiment, although the one accommodating part which accommodates the 1st-3rd thermosensitive element is provided in the inside, a partition wall is provided inside a housing | casing, and the 1st-3rd thermosensitive You may provide a pair of accommodating part which each accommodates an element separately. Moreover, although the inside of the accommodating part is made into the space by the air whose heat conductivity is lower than an insulating film, you may fill with the foamed resin whose heat conductivity is lower than an insulating film.
Moreover, in each said embodiment, although the insulating film is provided on the housing | casing installed in the upper surface of the board | substrate, an insulating film is directly installed in the upper surface of a board | substrate, and the 1st-3rd sensor part is installed. It may be provided.

  DESCRIPTION OF SYMBOLS 1,21 ... Infrared sensor, 2 ... Board | substrate, 3A ... 1st sensor part, 3B ... 2nd sensor part, 3C ... 3rd sensor part, 4,24 ... Light guide path part, 4a, 4b ... Outer wall part, 4c, 24c ... partition plate part, 5 ... housing (other member), 6, 36 ... insulating film, 7a ... first thermal element, 7b ... second thermal element, 7c ... third thermal element, 8A ... 1st wiring film, 8B ... 2nd wiring film, 8C ... 3rd wiring film, 9 ... Infrared reflective film, 24d ... Wide plate part, 36a ... Slit

Claims (4)

An infrared sensor that measures the temperature of two regions arranged opposite to a measurement object and arranged in the axial direction of the measurement object,
A substrate,
A first sensor part and a second sensor part which are heat sensitive parts provided on the upper surface of the substrate apart from each other;
A cylindrical light guide section having an opening above the first sensor section and the second sensor section and covering the periphery of the heat sensitive surfaces of the first sensor section and the second sensor section. Prepared,
The light guide path portion includes an outer wall portion surrounding the first sensor portion and the second sensor portion, an opening portion provided in the outer wall portion and above the first sensor portion, and the second sensor portion. Partitioning the opening above the sensor part and having a partition plate part higher than the outer wall part,
A third sensor part that is a heat sensitive part is provided immediately below the partition plate part on the upper surface of the substrate,
The light guide section is formed in a rectangular shape in plan view,
The partition plate portion is arranged in the center in the longitudinal direction of the light guide path portion ,
Outer wall part orthogonal to the longitudinal direction of the light guide path part among the outer wall parts is set lower than the outer wall part orthogonal to the lateral direction of the light guide path part,
The longitudinal direction of the light guide path portion is arranged along the axial direction,
An infrared sensor characterized in that an outer wall portion orthogonal to the longitudinal direction of the light guide path portion and an outer wall portion orthogonal to the lateral direction of the light guide path portion are both rectangular . The infrared sensor according to claim 1 ,
An infrared sensor characterized in that a front end portion of the partition plate portion is formed wide on the first sensor portion side and the second sensor portion side. The infrared sensor according to claim 1 or 2 ,
Insulating film installed on the upper surface of the substrate directly or through another member,
A first thermosensitive element provided on one surface of the insulating film on the substrate side of the insulating film;
A conductive first wiring film formed on one surface of the insulating film and connected to the first thermal element;
A second thermal element provided on the one surface of the insulating film and spaced apart from the first thermal element; and
A conductive second wiring film formed on one surface of the insulating film and connected to the second thermal element;
A third thermosensitive element provided on the one surface of the insulating film and immediately below the partition plate;
A conductive third wiring film formed on one surface of the insulating film and connected to the third thermal element;
An infrared reflection film provided on the other surface of the insulating film facing the third thermosensitive element;
The infrared sensor, wherein the infrared reflecting film and the partition plate portion are arranged with a gap therebetween. The infrared sensor according to claim 3 ,
The insulating film has a pair of slits formed between the first sensor unit and the third sensor unit and between the second sensor unit and the third sensor unit, respectively. An infrared sensor characterized by comprising:

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