JP3134090B2 - Tilt sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pot-shaped bottom plate provided on a package, a sphere placed on the pot-shaped bottom plate so as to be freely movable, and a detecting means provided at the center of the pot-shaped bottom plate. And a tilt sensor for detecting whether the package is tilted based on the detection / non-detection of the tilt.

[0002]

2. Description of the Related Art FIG. 15 is a sectional view showing the structure of a conventional tilt sensor. In FIG. 15, 1 is a substrate, 2 is a box-shaped package mounted on the substrate 1, and 3 is a package 2.
Is a through hole formed in the center of the pan-shaped bottom plate 3, 3 is a sphere freely movably placed on the pan-shaped bottom plate 3, and 5 is a movable part 5a. Through hole 3a
Is a microswitch attached to the substrate 1 in a state where the microswitch is located.

When the package 2 is not inclined horizontally as shown in FIG. 16, the through hole 3a of the pot-shaped bottom plate 3 is at the lowest position, and the sphere 4 is stabilized at the position of the through hole 3a by its own weight. The movable part 5a of the micro switch 5 is pushed down by the sphere 4, and it is detected that the package 2 is not tilted.

When the package 2 is tilted as shown in FIG. 17, the through hole 3a of the pot-shaped bottom plate 3 is positioned higher than the lowest position. However, the sphere 4 tends to stay at the lowest position due to its own weight, and as a result, the sphere 4 separates from the through-hole 3a. Therefore, the sphere 4 also separates from the movable portion 5a of the microswitch 5, and the movable portion 5a is attached. Since the package 2 is projected by the force, it detects that the package 2 is tilted.

When the package 2 is horizontal and the sphere 4 is pushing down the movable part 5a of the microswitch 5 as shown by a solid line in FIG. 18, the microswitch 5 is turned on and outputs "H" as shown in FIG. Then, as shown by the broken line in FIG. 18, at the stage where the package 2 is inclined and the sphere 4 separates from the movable part 5a and the movable part 5a protrudes, as shown in FIG. Output. That is, the microswitch 5 is of an ON / OFF digital output system.

[0006]

However, in the case of the above-described conventional tilt sensor, since the sphere 4 is in contact with the movable portion 5a of the microswitch 5, the microswitch 5 is damaged by repeated collisions. There was a fear. That is, there is a problem in durability as a tilt sensor.

When the package 2 is returned from the state shown in FIG. 17 in which the package 2 is inclined to the state shown in FIG. 16, the movable portion 5 a of the microswitch 5 is normally pushed down by the weight of the sphere 4. However, due to the degree of movement of the spherical body 4 and the frictional resistance and biasing force of the movable part 5a, the spherical body 4 remains in contact with the side surface of the protruding movable part 5a, and the movable part 5a is not pushed down. It may be in a state of protruding. That is, there is a problem in operation reliability.

Further, as an operation mode, the tilt / non-tilt can be detected only by ON / OFF of the micro switch 5 depending on whether or not the sphere 4 is pushing down the movable portion 5a, that is, only digitally. FIG.
When the movable portion 5a protrudes as in the case where the solid line changes from a solid line to a broken line, it is turned OFF (tilt detection),
No matter how far away from the movable part 5a, the OFF state continues. That is, there is only one ON / OFF switching point. In this case, the inclination degree cannot be adjusted for the user, and the user is likely to lack versatility.

The present invention has been made in view of such circumstances, and has as its object to provide a tilt sensor having high durability and high reliability.
It is an object of the present invention to provide a tilt sensor that allows a user to adjust a tilt degree.

[0010]

According to a first aspect of the present invention, there is provided a tilt sensor, wherein a pan-shaped bottom plate portion is provided on a package, a sphere is movably placed on the pan-shaped bottom plate portion, and the pan-shaped bottom plate portion is provided. A light-transmitting portion is provided at a central portion, and a reflective photo-interrupter is provided corresponding to the light-transmitting portion;
An analog detection circuit is connected to the light-receiving element of the
A variable resistor for adjusting the degree of inclination is provided in the detection circuit.
In the detection circuit, by adjusting the resistance value of the variable resistor
The detected voltage rises or falls in analog
It has a comparator for comparing with a reference voltage.
It is a sign.

[0011]

[0012]

According to the tilt sensor of the first aspect, the light emitted from the light emitting element of the reflection type photo interrupter enters the inside of the pot-shaped bottom plate portion through the light transmitting portion. At this time, if the sphere is located in the translucent portion (the center of the pot-shaped bottom plate portion), the reflected light from the sphere enters the light receiving element of the reflection type photointerrupter and generates an electric signal, and the sphere is present. That is, it detects that the package is not tilted. When the light reflected from the sphere does not enter the light receiving element, the absence of the sphere, that is, the inclination of the package is detected.

The reflection type photointerrupter is not a contact type as in a conventional microswitch but a non-contact type, so that the durability as a tilt sensor is excellent. Also, since there is nothing protruding toward the pot-shaped bottom plate like the movable part of the conventional microswitch, the sphere moves smoothly, and when the package returns to the horizontal position, the sphere is always in the center of the pot-shaped bottom plate. And the operation reliability is high.

[0014] Then, since the detection circuit of analog type which includes a variable resistor as an output variable portion to the light receiving element of the reflection type photo-interrupter is connected, the user at the output variable region
By adjusting a certain variable resistance, the degree of inclination can be adjusted in an analog manner, and versatility is expanded.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the tilt sensor according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a plan view of the tilt sensor according to the embodiment, FIG. 2 is a front view as viewed from a direction C, FIG. 3 is a side view as viewed from a direction D, and FIG. 5 is a sectional view taken along line BB '.

A pot-shaped bottom plate 12 is attached to a box-shaped package 11 with the concave portion facing upward. A glossy iron sphere 13 is movably placed on the upper surface of the pot-shaped bottom plate 12. A through-hole is formed in the central portion, which is the lowest position of the pot-shaped bottom plate portion 12, to serve as a light-transmitting portion 12a. The box-shaped package 11 is mounted on a substrate 14. A reflection type photo interrupter 15 is attached to the substrate 14 corresponding to the light transmitting portion 12a. 16 is the substrate 1
4 are legs integrally formed on the bottom surface.

FIG. 6 shows an analog detection circuit 17. 15a is a light emitting element of the reflection type photo interrupter 15, and 15b is a light receiving element. The light emitting element 15a is constituted by a light emitting diode, and the light receiving element 15b is constituted by a phototransistor. In the detection circuit 17, R ₂ is a variable resistance as a variable output section is connected to the emitter of the light receiving element (phototransistor) 15b. 1
Reference numeral 8 denotes a comparator, which includes a light receiving element 15b and a variable resistor R
Detection voltage V _E generated to a connection point between the ₂ is supplied to the non-inverting input terminal (+). R ₃ and R ₄ are voltage _dividing resistors for generating a reference voltage V _th , and the reference voltage V _th is
Are supplied to the inverting input terminal (−) of the first embodiment. R ₅ is a feedback resistor to have a hysteresis to prevent chattering.

FIG. 7 shows a state in which the package 11 is horizontal and the sphere 13 is located in the light transmitting portion 12a. At this time, the light emitted from the light emitting element 15a of the reflection type photo interrupter 15 is reflected by the sphere 13 via the light transmitting portion 12a, and the reflected light is incident on the light receiving element 15b of the reflection type photo interrupter 15. Since the photocurrent generated in the light receiving element 15b is large, the detection voltage _VE is also large and the reference voltage _Vth
, The comparator 18 outputs “H” to detect that the package 11 is horizontal (or the inclination is small).

FIG. 9 shows a state in which the package 11 is tilted in the left-right direction (tilt angle θ ₁ ), and FIG. 10 shows a state in which the package 11 is tilted in the front-rear direction (tilt angle θ ₂ ). Show. FIG. 8 is an enlarged view of the state. The light emitted from the light emitting element 15a of the reflective photointerrupter 15 is not reflected by the sphere 13, so that no or little photocurrent flows through the light receiving element 15b.
Below the detection voltage V _E is the reference voltage V _th, the comparator 18 outputs a "L", detects that the package 11 is inclined.

Since the reflection type photointerrupter 15 is a non-contact type, it has higher durability than a conventional microswitch which is a contact type. In addition, since there is nothing protruding from the bottom surface of the pot-shaped bottom plate portion 12 like the movable portion of the conventional microswitch, the movement of the sphere 13 is smooth, and when the package 11 returns to the horizontal position, the sphere 13 is surely placed in the pot. It returns to the light transmitting part 12a at the center of the bottom plate part 12, and the operation is highly reliable.

FIG. 11 shows a change in the position of the sphere 13, and FIG.
Reference numeral 2 denotes the intensity of the photocurrent of the light receiving element 15b corresponding to the position change. hh ′ indicates the directional angle of the reflective photointerrupter 15. The sphere 13 is a ₀ ,
a _1, relative to change in position with a _2, a _3, photocurrent decreases analog manner gradually.

The light emitted from the light emitting element 15a of the reflection type photo interrupter 15 enters the inside of the pot-shaped bottom plate 12 through the light transmitting part 12a, and the light reflected by the sphere 13 is incident on the light receiving element 15b, and the light receiving element 15b in photoelectric current is generated, this photocurrent is detected voltage V _E generated by flowing through the variable resistor R _2. When the detection voltage V _E is higher than the reference voltage V _th , the output of the comparator 18 becomes “H”, and the sphere 13 is close to the light transmitting portion 12a, that is, the package 11 is horizontal or not inclined very much. Is detected.

When the package 11 is inclined and the sphere 13 moves away from the light transmitting portion 12a, the light reflected from the sphere 13 decreases, the photocurrent by the light receiving element 15b decreases, and the detection voltage V
_E also decreases. When the detection voltage V _E is lower than the reference voltage V _th , the output of the comparator 18 becomes “L”, and it is detected that the package 11 has tilted.

[0025] Here, increasing the resistance value by adjusting the variable resistor R _2, an analog to increased detection voltage V _E is corresponding to the resistance value increase, when higher than the reference voltage V _th , The output of the comparator 18 becomes “H”. That is, even if the degree of inclination of the package 11 is large to some extent, it is possible not to detect that the package 11 is inclined at the degree of inclination. Conversely, by lowering the resistance value of the variable resistor R _2, analog lowered correspondingly the detection voltage V _E to the resistance decrease, is lower than the detection voltage V _E is the reference voltage V _th comparator When the output of 18 becomes "L", it can be detected that the package 11 is inclined even if the degree of inclination of the package 11 is small. The degree of inclination to be detected depends on
Depending on the user's wish. The operation is carried out by adjusting the variable resistor R _2.

FIG. 13 shows another detection circuit 19. 20 is a differential amplifier circuit, D ₁ is a backflow prevention diode, D ₂ and D ₃
Is a diode for voltage drop, C ₁ is a capacitor for peak hold, R ₆ is a variable resistor for adjusting the degree of inclination, R ₇
Is a voltage dividing resistor, Tr ₁ is a control transistor, and Tr ₂ is an output transistor.

FIG. 14 is a waveform diagram for explaining the operation of the detection circuit 19 of FIG. The photocurrent of the light receiving element 15b is converted into a voltage, and the voltage of z is obtained through the amplifier circuit 20. The gradual drop in the voltage z indicates that the photocurrent gradually decreases due to aging and temperature changes. Voltage y
Is obtained by peak-holding the voltage z and then dividing the resistance by the variable resistor R ₆ and the voltage dividing resistor R ₇ . Voltage x is voltage y
Is a voltage reduced by one diode. Voltage w than that voltage z diode 2 min lowered, the threshold of the output transistor Tr _2, and gradually reduced in accordance with the voltage z which gradually decreases. Voltage w is voltage x
When below the output conducting transistor Tr ₂ is becomes "H".

The depression of the voltage z is a result of the decrease in the photocurrent of the light receiving element 15b due to the movement of the sphere 13 from the light transmitting portion 12a. As the voltage z decreases, the voltage w also decreases, and this voltage w
The voltage x is higher than the
r ₂ conducts and outputs “H”.

The voltage y and thus the voltage x can be varied by adjusting the variable resistor R ₆ , whereby the degree of inclination when the inclination is detected can be adjusted.

In the above embodiment, the through hole is formed in the pot-shaped bottom plate portion 12 as the light transmitting portion 12a, but the through hole may be filled with a transparent resin.

[0031]

According to the tilt sensor according to the first aspect of the present invention, since the reflection type photo interrupter is a non-contact type, the durability as the tilt sensor is higher than that of the conventional contact type micro switch. And the sphere moves smoothly because there is nothing protruding into the pot-shaped bottom plate like the movable part of the microswitch.
When the package returns to a horizontal position, the sphere always returns to the light-transmitting portion at the center of the pot-shaped bottom plate portion, so that the reliability of operation can be increased.

[0032] Since is connected a detection circuit of the analog type with variable resistance as a variable output section to the light receiving element of the reflection type photo-interrupter, the user variable output section
By adjusting the variable resistance, the degree of inclination can be adjusted in an analog manner, and the versatility can be expanded.

[Brief description of the drawings]

FIG. 1 is a plan view of an inclination sensor according to an embodiment of the present invention.

FIG. 2 is a front view of the tilt sensor according to the embodiment.

FIG. 3 is a side view of the tilt sensor according to the embodiment.

FIG. 4 is a sectional view taken along line AA ′ in FIG. 1;

FIG. 5 is a sectional view taken along line BB ′ in FIG. 1;

FIG. 6 is a circuit diagram illustrating an analog detection circuit according to the embodiment.

FIG. 7 is an enlarged view of a state where a sphere is located in a light transmitting portion in the embodiment.

FIG. 8 is an enlarged view of a state where a sphere is separated from a light transmitting part in the embodiment.

FIG. 9 is a front view when the package is inclined in the left-right direction in the embodiment.

FIG. 10 is a side view when the package is inclined in the front-rear direction in the embodiment.

FIG. 11 is a diagram showing a change in the position of a sphere in the example.

FIG. 12 is a graph showing a photocurrent intensity of a light receiving element corresponding to a change in the position of a sphere in the example.

FIG. 13 is a circuit diagram showing another embodiment of the analog detection circuit.

14 is a waveform chart illustrating the operation of the detection circuit in FIG.

FIG. 15 is a cross-sectional view illustrating a configuration of a conventional tilt sensor.

FIG. 16 is an enlarged view of a conventional example when it is not tilted.

FIG. 17 is an enlarged view of the conventional example when tilted.

FIG. 18 is a cross-sectional view showing a difference between detection and non-detection in a conventional example.

FIG. 19 is a graph showing a difference between a detected output and a non-detected output in the conventional example.

[Explanation of symbols]

11: Package 12: Pot-shaped bottom plate 12a: Translucent portion (through hole) 13: Spherical 14: Substrate 15: Reflective photo interrupter 15a: Light emitting element 15b: Light receiving element 17: Detection circuit 19: … Detector circuit R ₂ … Variable resistance (variable output) R ₆ … Variable resistance (variable output)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-259412 (JP, A) JP-A 5-69618 (JP, U) JP-A 5-38517 (JP, U) (58) Investigation Field (Int. Cl. ⁷ , DB name) G01C 9/00-9/36

Claims (1)

(57) [Claims] 1. A pan-shaped bottom plate portion is provided on a package, a sphere is movably placed on the pan-shaped bottom plate portion, and a light-transmitting portion is provided at the center of the pan-shaped bottom plate portion. To provide a reflective photointerrupter.
An analog detection circuit is connected to the
A variable resistor for adjusting the degree of inclination is provided in the output circuit.
In the detection circuit, by adjusting the resistance value of the variable resistor
The detected voltage rises or falls in analog
A tilt sensor comprising a comparator for comparing with a reference voltage .