JP2001324388A - Infrared sensor mechanism and microwave oven using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared temperature sensor capable of being loaded on even a small microwave oven, and having a small and simple formation, and high reliability relative to a noise or a pollutant. SOLUTION: In this sensor mechanism, a pyroelectric infrared sensor 11 formed by lining up longitudinally four photosensitive parts 13a, 13b, 13c, 13d inside an inner cylinder 4 which is a metal cylindrical vessel is stored, and an infrared ray transmission hole 4e is bored corresponding to the photosensitive parts, and an infrared ray transmission hole 5c and a shielding wall 5d are lined up alternately on the side of a coaxial outer cylinder enveloping the inner cylinder 4 in a nesting shape, and relative rotational speed between the inner cylinder 4 and the outer cylinder 5 is differentiated by rotation transmission means 5g, 7, 8, 9 receiving the movement of a periodically repeatedly rotating motor 6. The infrared ray transmission holes 5c and the shielding wall 5d are rotated around the inner cylinder 4, to perform a role of a chopper, and to thereby enable flat temperature measurement. The sensor mechanism has a small and simple formation having a single motor, and thereby can be loaded on a small microwave oven and has high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared sensor mechanism, and more particularly to a case where the same sensor structure is used in a microwave oven.

[0002]

2. Description of the Related Art There have long been attempts to measure the surface temperature of a food to be heated with an infrared sensor to automate cooking, and various ideas have been proposed. As a new direction, Japanese Patent Application Laid-Open No. 7-98123 discloses an example in which the conventional point measurement is extended to a line measurement. More recently, two stepping motors are used and rotated in two directions vertically and horizontally to make the inside of the heating chamber planar. Even scanning microwave ovens are commercially available.

[0003]

However, the expansion of the measurement range inevitably leads to an increase in the size and complexity of the mechanism, which is incompatible with the ongoing miniaturization of microwave ovens. Although it is particularly easy to forget, the lead lines that take out the output of the infrared element to the outside occupy a large part of the size and complexity. The weak signal of the infrared sensor is extracted to the outside using the shield wire, but if the extraction position is far away from the center of rotation, the locus of the shield wire drawn by the rotation will increase in proportion to the distance from the center Become. According to the technical standards of the Electrical Appliance and Material Control Law, it is obligatory to take measures to prevent the internal wiring of the equipment from touching the movable parts, so if the shielded wire moves, remove any objects that may touch the surroundings. No.

The above-mentioned infrared sensor for scanning in a planar manner is a kind of thermocouple series multiple connection element called a thermopile, which is generally strictly electrostatic when used in an environment where the output voltage is low and the noise is extremely large like a microwave oven. Since shielding is required, an increase in size is unavoidable in that respect. On the other hand, in order to use a pyroelectric infrared sensor, which is relatively inexpensive, has a high output voltage, and does not require strict shielding, a mechanism called a chopper, which intermittently blocks infrared rays, is essential. If this intermittent operation is performed by a motor, the number of motors becomes three for convenience, and the mechanism becomes more complicated.

[0005] Generally, a microwave oven employs a configuration in which ambient air is actively taken in for cooling a magnetron.
Moreover, since it is common sense to install in a kitchen where smoke, soot, oil vapor, salt, alcohol and vinegar (acetic acid) are scattered, the adoption of a complicated and precise movable mechanism causes a failure. In addition, steam, oil, juice splashes from the heated food itself,
Since food debris and the like are scattered, this is also a source of contamination, and the failure occurrence rate of the infrared sensor temperature measurement mechanism disposed in the shortest distance may be further deteriorated.

According to the present invention, as an infrared sensor temperature measuring mechanism employed in a microwave oven which must be used under poor conditions in terms of dirt, the shielded wire drawn out has a simple structure that is unlikely to cause a failure and operates. Accordingly, it is an object of the present invention to provide an infrared temperature measuring mechanism capable of reducing a range of a locus to be drawn and measuring a planar temperature.

[0007]

The present invention employs the following means in order to solve the above-mentioned problems.

[0008] Two cylindrical containers having an inner cylinder and an outer cylinder which are coaxially and movably supported at both end surfaces in a nested state, a pyroelectric infrared sensor housed in the inner cylinder, and connected to the infrared sensor. And a rotation transmitting means provided between the motor, the inner cylinder and the outer cylinder, and the infrared sensor is arranged in the axial direction of the inner cylinder. A plurality of photosensitive portions along the shield line, the shield line penetrates the inside of one shaft of the inner cylinder, and an infrared transmission hole is opened at a position corresponding to the photosensitive portion of the infrared sensor on a side surface of the inner cylinder. A plurality of infrared transmission holes and a shielding wall are provided on the side of the cylinder, and the rotation transmitting means has a different relative peripheral speed between the inner cylinder and the outer cylinder.

According to the present invention, the infrared sensor having a plurality of photosensitive portions in the axial direction is housed in the inner cylinder having the infrared transmitting holes corresponding to the photosensitive portions opened in the side surface, and is rotated by the motor which rotates periodically reciprocally. Since the infrared sensor is linked by the transmission means, the infrared sensor also rotates reciprocally. The field of view of the photosensitive section of the infrared sensor is formed by a plurality of photosensitive sections arranged along the axial direction and the periodic reciprocating rotation about the axis. In addition, a plurality of infrared transmitting holes and a shielding wall are provided on the side of the outer cylinder in which the inner cylinder is coaxially nested, and the outer cylinder rotates at a different peripheral speed from the inner cylinder, so that the outer cylinder functions as a chopper. . Furthermore, since the lead wire of the infrared sensor passes through one shaft of the inner cylinder and is drawn out, it is not swung by the periodic reciprocating rotation of the inner cylinder, it is only twisted, and a large space around is required. do not do.

That is, despite having a simple structure having one motor, it has a planar field of view and also has a chopper function, so that an inexpensive pyroelectric infrared sensor having a large output voltage can be adopted. Since a large space is not required, a temperature measurement mechanism that can be used in a poor environment and that can be mounted on a microwave oven that is being reduced in size and weight can be realized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to two cylindrical containers having an inner tube and an outer tube which are coaxially and movably supported at both end surfaces in a nested state, and a pyroelectric infrared sensor housed in the inner tube. And a shield wire connected to the infrared sensor, a motor that rotates periodically reciprocally, and a rotation transmitting unit provided between the motor and the inner cylinder and the outer cylinder. It has a plurality of photosensitive portions along the axial direction of the inner cylinder, the shield wire passes through the inside of one axis of the inner cylinder, and the inner cylinder side surface has infrared rays at a position corresponding to the photosensitive portion of the infrared sensor. A transmission hole is formed, a plurality of infrared transmission holes and a shielding wall are provided on the outer cylinder side surface, and the rotation transmitting means has a different relative peripheral speed between the inner cylinder and the outer cylinder.

Thus, an infrared sensor having a plurality of photosensitive portions in the axial direction is accommodated in an inner cylinder having infrared transmitting holes corresponding to the photosensitive portions opened in the side surface, and a rotation transmitting means is provided to a motor which reciprocates periodically. , The infrared sensor also reciprocates periodically. The field of view of the photosensitive section of the infrared sensor is formed by a plurality of photosensitive sections arranged along the axial direction and the periodic reciprocating rotation about the axis. In addition, a plurality of infrared transmission holes and shielding walls are provided on the side of the outer cylinder with the inner cylinder coaxially nested, and the outer cylinder rotates at a different peripheral speed from the inner cylinder, so the outer cylinder functions as a chopper I do. Further, since the lead wire of the infrared sensor passes through one shaft of the inner cylinder and is drawn out, it is not swung by the periodic reciprocating rotation of the inner cylinder, and does not require a large space around.

In other words, despite the simple structure having one motor, it has a planar field of view and also has a chopper function, so that an inexpensive pyroelectric infrared sensor with a large output voltage can be adopted, Since a large space is not required, there is an effect that a temperature measuring mechanism that can be mounted in a microwave oven that is used in a poor environment and that is being reduced in size and weight can be realized.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a plan view showing an infrared sensor mechanism according to an embodiment of the present invention, FIG. 1B is a front view thereof, and FIG.
(C) is the same side view. A pair of inverted L-shaped sheet metal fittings 1 and 2 are fixed with screws 3 and constitute two parallel surfaces.
An inner cylinder 4 as a metal cylindrical container is rotatably supported between the two parallel surfaces by penetrating an upper shaft 4a and a lower shaft 4b through holes coaxially formed in the two parallel surfaces. Upper shaft 4
The so-called D-cut in which a part of the circumference is replaced by a straight line is applied to the axial cross section of a. The outer cylinder 5 is mounted coaxially with the upper shaft 4a and the lower shaft 4b so as to be rotatable while wrapping the inner cylinder 4 inside like a nest. The motor 6 is mounted on the upper surface of the mounting bracket 1 with its shaft 6a penetrating downward.
Two gears having different numbers of teeth, a drive gear A7 having a small number of teeth, and a drive gear B8 having a large number of teeth are coaxially fixed to the shaft 6a at a position near the motor 6 and at a position far from the motor 6. In order to fit these, a passive gear A9 fixed to the upper shaft 4a is attached to the drive gear A7.
The driving gear B8 is provided with a passive gear B5g described later. Further, a shield wire 10 connected to an infrared element described later penetrates through the inside of the lower shaft 4b and is drawn out.

(C) Four small circles drawn by broken lines in the center of the side view are infrared devices described later, and are arranged in a straight line with the photosensitive portions 13a, 13b, 13c, and 13d from above. An ellipse surrounding this is an infrared transmitting hole 4e opened in the side surface of the inner cylinder 4, and the positional relationship between them is fixed. Further, an ellipse drawn outside is an infrared transmitting hole 5 opened in the side surface of the outer cylinder 5.
c, which is slightly larger than the hole 4e. Since the outer cylinder 5 is relatively rotated with respect to the inner cylinder 4, the state shown in FIG. 1C where the two ellipses coincide with each other occurs only instantaneously.

FIG. 2 is an exploded front view in a vertically disassembled state in order to clarify the positional relationship between the components, and they are integrated by being superposed along a line. The metal inner cylinder 4 located at the center is composed of an upper shaft 4a, a lid 4c formed integrally therewith, and a container 4d formed integrally with a lower shaft 4b, and a container with an infrared sensor 11 inserted therein. Cover 4c on part 4d
And fix it. An oblong infrared transmitting hole 4e is opened in the circumferential side surface of the container 4d, and the photosensitive portion of the infrared sensor 11 is fixed to face the hole 4e. The lower shaft 4b has a coaxial through hole 4f.

The container 5b and the lid 5a of the outer cylinder 5 are mounted coaxially and rotatably in a state where the inner cylinder 4 is completely covered in a nested manner. Eight infrared transmitting holes 5c are formed on the side surface of the outer cylindrical container portion 5b at equal intervals on the circumference. The hole 5c is slightly larger than the hole 4e, and a wall located between the two adjacent infrared transmitting holes 5c has a size to cover the infrared transmitting hole 4e, and in that sense, is a shielding wall 5d. A hole 5e coaxial with the outer cylinder 5 is formed in the bottom of the container portion 5b, and the diameter of the hole 5e is made slightly larger than the diameter of the lower shaft 4b of the inner cylinder 4 so as to smoothly rotate the two. Similarly, a hole 5f having a diameter slightly larger than the diameter of the upper shaft 4a of the inner cylinder 4 is provided coaxially with the outer cylinder 5 in the lid 5a. In addition, the passive gear B5g is provided on the upper portion of the lid 5a so as to be coaxial with the outer cylinder 5 by integral molding with the lid 5a.

Coaxial holes 1a and 2a are formed in the pair of sheet metal fittings 1 and 2, respectively. Respectively slightly larger. The diameter of a hole 9a formed at the center of the passive gear A9 is slightly larger than the upper shaft 4a of the inner cylinder 4, and the shape of the hole is a D-shape that fits with the upper shaft. The lid 5a of the outer cylinder 5 and the container 5b are fitted and fixed in a state of nesting the inner cylinder 4 in a nested manner. Sheet metal fixture 1
After fixing the motor 6 on the shaft of the motor 6 and inserting the drive gears A7 and B8 on the shaft of the motor 6 and fixing them by bonding or the like, the nested inner cylinder 4 and outer cylinder 5 were inserted into the holes 1a and 2a, respectively. In this state, a pair of sheet metal fittings 1 and 2 are fixed with screws 3. At that time, the passive gear A9 is inserted into the upper shaft 4a. FIG. 1 shows this state.

FIG. 3A is a plan view of the infrared sensor 11, FIG. 3B is a front view thereof, and FIG. 3C is a side view thereof. The infrared sensor 11 includes a printed circuit board 12, a pyroelectric infrared device main body 13, and a resin lens 14. The printed board 12 is a plate cut into a substantially H-shape.
The upper and lower two legs of the character are inserted into a pair of slits provided on a lid 4a of the inner cylinder 4 and a pair of slits provided on the bottom of the container 4b. The sensor body 13 is fixed to the printed circuit board 12 by soldering, and four photosensitive portions 13a, 13b, 13c, and 13d are lined up in a straight line in the vertical direction in FIG.

The resin lens 14 is inserted and fitted into a hole (not shown) formed in the printed circuit board 12 at a position corresponding to the resin lens 14 by a pair of claws 14a, and is fixed.
The lens 14 is composed of two lenses each having a focal point. One focal point is located at a bisector of the photosensitive portions 13a and 13b, and another focal point is located at a bisecting point of 13c and 13d. A light-shielding plate 14b is provided between the two lenses so that each lens corresponds to only two photosensitive portions. As illustrated in the side view (c) of FIG. 3, the field of view of the photosensitive unit 13 b is located at the uppermost position due to the difference in the viewing angle of the object of each photosensitive unit.
The field of view 3a is followed by the field of view 13d, and the field of view 13c at the bottom. These four fields of view are
Draw four circles arranged at equal intervals on a straight line on a plane separated by about 00 mm.

FIG. 4 shows the inner cylinder 4 just before fitting, and FIG. 4A is a plan view of the upper shaft 4a and the lid 4c.
4B is a front view of the same, FIG. 4C is a front view of the container 4d and the lower shaft 4b, and FIG. 4D is a bottom view of the same. Lid 4c
, A pair of slits 4h is opened, and a pair of slits 4k is similarly opened at the bottom of the container 4d. The pair of feet above the H-shaped part of the printed circuit board 12 is inserted into the slit 4h, and the pair of feet below the H-shaped part is inserted into the slit 4k.

The motor 6 employs a stepping motor. The drive circuit and the reverse repetitive rotation operation method are known,
Omitted because it becomes complicated. Since the configuration of the microwave oven main body, the method of mounting the infrared sensor, and the like are also known, they are also omitted, and the operation of the present embodiment will be described.

When the drive shaft 6a of the motor 6 rotates, the two drive gears A7 and B8 fixed thereto also rotate,
The passive gear A9 and the gear 5g engaged with this also rotate.
Since the number of teeth of the driving gear A7 is smaller than the number of teeth of the driving gear B8, the passive gear A9 that fits them rotates at a lower speed than the passive gear B5g. The passive gear A9 is inserted into the upper shaft 4a of the inner cylinder 4 through the hole 9a, and the entire inner cylinder 4 rotates in synchronization with the passive gear A9 by fitting each other in a D shape. On the other hand, since the passive gear B5g is integrally formed with the cover 5a of the outer cylinder 5, the entire outer cylinder 5 also rotates in synchronization with the passive gear B5g. The outer cylinder 5 rotates at a higher speed than the inner cylinder 4.

If the motor 6 rotates repeatedly in the reverse direction, the inner cylinder 4 also rotates by an angle proportional to the ratio of the number of teeth, and the outer cylinder 5 rotates at a higher speed than the inner cylinder, and therefore at a larger angle than the inner cylinder. I do.
Infrared transmitting holes 5c are formed at equal intervals around the entire circumferential side surface of the outer cylinder 5, and the shielding wall 5d located between the two adjacent holes 5c is larger than the infrared transmitting hole 4e of the inner cylinder 4.
Is rotated at a higher speed than the inner cylinder 4, so that light passing through the infrared transmitting hole 4e on the side surface of the inner cylinder is intermittently blocked. Therefore, the pyroelectric infrared sensor 11 fixed to face the infrared transmission hole 4e generates an output voltage corresponding to the amount of incident infrared light.

FIG. 5 is a front view of a disassembled state showing another embodiment, and is integrated by being superposed along a line. FIG. 5 corresponds to FIG. The differences from FIG. 2 are the position and drive of the motor 6, the shape of the passive gear, the number of teeth, and the like. The motor 6 is fixed coaxially with the outer cylinder and the inner cylinder, and a so-called D-cut is applied to the shaft 6a. A fitting hole into which the shaft 6a can be inserted is provided at the center of the upper shaft 4a of the inner cylinder 4, and is inserted and connected. A so-called D-cut is also applied to the outer cylinder, and the outer cylinder is connected to the internal gear 15 having a hole to be fitted therewith. In addition to a passive gear 5g integrally formed, a planetary gear 16 for connecting the internal gear 15 and the passive gear 5g is attached to the lid 5a of the outer cylinder 5. The center shaft of the planetary gear 16 is integrally formed with the lid 5a, and the center of the lid 5a is
A hole 5f having a diameter slightly larger than the diameter of a is formed.

The operation of this embodiment is as follows. With the rotation of the drive shaft 6a of the motor 6, the inner cylinder 4, which is D-cut connected thereto, rotates synchronously, and the internal gear 15, which is D-cut connected to the upper shaft 4a, also rotates synchronously. Motor 6
For example, if the drive shaft 6a is rotated clockwise by 45 degrees, the inner cylinder 4 and the internal gear 15 are also rotated clockwise by 45 degrees. Assuming that the reference pitch circle diameter of the planetary gear 15 is half of that of the internal gear 15, the planetary gear 15 turns 90 degrees clockwise, and the passive gear 5g engaging with this rotates 90 degrees counterclockwise. . When the motor 6 performs the reverse rotation repetitive rotation operation, the inner cylinder 4 performs the reverse rotation repetitive rotation in synchronization with this, and the outer cylinder 5 repeatedly rotates in the reverse direction at twice the speed. Accordingly, the infrared transmitting hole 5c periodically opened outside the infrared transmitting hole 4e.
And the shielding wall 5d alternately traverse, and the four photosensitive portions 13
The four circles on a straight line drawn by the visual fields a, b, c, and d form a plane by this rotation.

The difference between the embodiments of FIGS. 2 and 5 is the difference in the relative speed of the outer cylinder 5 with respect to the inner cylinder 4. In the example of FIG. 2, the rotation direction of the outer cylinder 5 is the same as that of the inner cylinder 4, and the speed of the outer cylinder 5 is large.
In the example of FIG. 5, the rotation direction of the outer cylinder 5 is opposite to that of the inner cylinder 4. In any case, the outer cylinder 5 is rotated with respect to the inner cylinder 4, and the outside of the infrared transmission hole 4 e of the inner cylinder 4 is connected to the infrared transmission hole 5 c on the side of the outer cylinder 5.
And the shielding wall 5d cross alternately. In other words, it works as a chopper. Since the photosensitive portions 13a, 13b, 13c, and 13d of the pyroelectric infrared device main body 13 are arranged in the rotation axis direction, if the trajectories drawn by the rotation of the respective photosensitive portions are added together, a surface is formed, and at the same time, all the photosensitive portions are formed. Since the infrared transmission hole 5c and the shielding wall 5d make the same movement with respect to the part,
Exactly the same chopping is performed on the four photosensitive units,
As a result, the same output is obtained for an infrared input from the same temperature.

The shield wire 10 is formed in the hole 4 of the lower shaft 4b of the inner cylinder 4.
Since it is pulled out from f, it is only twisted with the repetitive reverse rotation, and there is no position change due to the rotation. Therefore, even if the components are arranged close to the periphery of the shielded wire 10, they do not come into contact with each other by rotation, so that the entire apparatus shown in FIG. 1 can be stored in a small space of a small microwave oven. In addition, the infrared sensor 11
Is stored inside the metal inner cylinder 4 and is protected from the noise of the microwave oven.

In this embodiment, the infrared temperature element having four photosensitive portions is used to enable the surface temperature measurement. However, the linear temperature measurement using an element having only one photosensitive portion is also applicable. Scan and chop with one motor,
The effect of small size and high reliability is maintained. Eight infrared transmitting holes 5c on the side surface of the outer cylinder 5 and a shielding wall 5d sandwiched in the middle are also eight.
When the outer cylinder 5 is continuously rotated, the infrared transmission holes 5c and the shielding walls 5d alternately pass at regular intervals in front of the infrared transmission holes 4e of the inner cylinder 4 when the outer cylinder 5 is continuously rotated. . Therefore, as compared with the case where the gears are arranged in a non-endless state, an appropriate chopping speed can be realized by appropriately setting the number of teeth of the driving and passive gears, and the degree of freedom in design is expanded.

Although the description of this embodiment has been made on the premise that the microwave oven is mounted on the microwave oven, the present invention is not necessarily limited to the microwave oven.
The effect that the single chopper and the reverse repetitive rotation can be shared by one motor is obtained even with the infrared sensor mechanism alone.

In this embodiment, the case where the infrared sensor mechanism of the present invention is mounted on a microwave oven is described. However, the present invention is not limited to this, and it is needless to say that the infrared sensor mechanism can be used in other cookers or other fields. .

[0033]

As described above, according to the present invention, a planar temperature measurement can be performed with a small and simple structure using only one motor, and the shielded wire does not move because it is twisted only.
It can be installed in a small microwave oven.

[Brief description of the drawings]

FIG. 1A is a plan view showing an infrared sensor mechanism according to an embodiment of the present invention. FIG. 1B is a front view showing the infrared sensor mechanism. FIG. 1C is a side view showing the infrared sensor mechanism.

FIG. 2 is an exploded front view showing the infrared sensor mechanism.

3A is a plan view of the infrared sensor; FIG. 3B is a front view of the infrared sensor; FIG.

4A is a plan view of an upper shaft and a lid of the inner cylinder of the infrared sensor mechanism. FIG. 4B is a front view of the infrared sensor mechanism. FIG. 4C is a front view of the inner cylinder of the infrared sensor mechanism. (D) Bottom view of the infrared sensor mechanism

FIG. 5 is an exploded front view showing an infrared sensor mechanism according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 4 inner cylinder 4e infrared transmission hole 5 outer cylinder 5c infrared transmission hole 5d shielding wall 5g passive gear B (rotation transmission means) 6 motor 7 drive gear A (rotation transmission means) 8 drive gear B (rotation transmission means) 9 Passive gear A (rotation transmitting means) 10 Shield wire 11 Infrared sensor 13a, 13b, 13c, 13d Photosensitive unit

Claims (2)

[Claims] 1. A cylindrical container comprising an inner cylinder and an outer cylinder in a nested state supported on both ends coaxially and movably, a pyroelectric infrared sensor housed in the inner cylinder, and connected to the infrared sensor. And a rotation transmitting means provided between the motor, the inner cylinder and the outer cylinder, and the infrared sensor is arranged in the axial direction of the inner cylinder. A plurality of photosensitive portions along the shield line, the shield line penetrates the inside of one shaft of the inner cylinder, and an infrared transmission hole is opened at a position corresponding to the photosensitive portion of the infrared sensor on a side surface of the inner cylinder. An infrared sensor mechanism wherein a plurality of infrared transmitting holes and a shielding wall are provided on a side surface of the cylinder, and the rotation transmitting means has different relative peripheral speeds of the inner cylinder and the outer cylinder. 2. A microwave oven using the infrared sensor mechanism according to claim 1.