JPH04252511A - Object sensor - Google Patents

Abstract

PURPOSE:To attain the adjustment with higher precision not depending on manual operation by avoiding a personal error and much time which have been caused in a conventional sensor because the sensitivity adjustment of the object sensor has been depending on manual work. CONSTITUTION:The measurement device is provided with a level change means which automatically and gradually increases or decreases an output level of a transmission signal at a transmission element 1 and when a reception signal by a reception element 2 exceeds a reference level, an output level just before the excess is kept and the level is used as a transmission output level of the actual transmission element. The transmission signal level corresponding to the reflecting state of an installation site of a device and the device itself is set properly, and malfunction such that a sensor senses an access of a hand or the like in mistake without access of an object is avoided. Thus, the adjustment with higher precision is attained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object sensing sensor equipped with a sensitivity adjustment circuit.

0002

[Prior Art] There are two types of sensors that detect the presence or absence of human hands: reflective sensors and transparent sensors. However, reflective sensors are often used in automatic cleaning equipment due to restrictions on sensor installation. .

[0003] FIG. 1 shows an example of this, and a reflective human body sensing sensor is composed of a light projecting element 1 and a light receiving element 2. When this sensor S is applied to an automatic water faucet as shown in FIG. 2, for example, the sensor S is attached near the spout 4 of the spout 3 attached to the washbasin 5. Then, a human hand opens the water spout 4.
When it approaches the lower part, it senses this and drives the water discharge valve etc.
Wash your hands by squirting water from the spout. If you remove your hand, the water will stop spouting after a certain period of time.

[0004] In such an automatic faucet, the sensing adjustment is performed by a person manually adjusting the light receiving sensitivity and the volume at the time of shipment and installation.

[0005]

[Problem to be Solved by the Invention] Generally, if the sensitivity is too low, the hand cannot be detected, so it is often set to a high value. The light receiving element often erroneously senses the reflected light from the surface of the ball 6 due to differences in shape and color, degree of unevenness of the surface of the ball 6, special circumstances at the installation site, etc. In addition, adjustments were made manually, which required a lot of man-hours and caused individual differences.

[0006] In order to solve the above-mentioned problems, the present invention has the following features:
This automates the sensing adjustment and enables more accurate adjustment without relying on human hands.

[0007]

[Means for Solving the Problems] An object sensing sensor of the present invention includes a transmitting element that outputs a transmitted signal, and a receiving element that inputs a received signal reflected by an object among the transmitted signals, In an object sensing sensor that detects the presence of the object based on a comparison between the strength of the reception signal received by the element and a reference value, the output level of the transmission signal in the transmission element, the reception sensitivity of the reception signal in the reception element, or the It is characterized by comprising level changing means for automatically gradually increasing or decreasing a reference value, and means for holding the output level, reception sensitivity, or reference value at the time when the received signal exceeds or is about to exceed the reference level. do.

[0008] As for the types of sensors, infrared sensors, visible light sensors, ultrasonic sensors, and other reflective proximity sensors can be used.

[0009]

[Operation] When installing a device on-site that already has an object-sensing sensor installed, or when installing an object-sensing sensor on a device at the site, if the level change means is activated when no object is nearby, the transmission from the transmitting element will be The level of the signal increases linearly or stepwise. The receiving element receives a reflected signal from the equipment, and when the level exceeds the reference level, the level changing means changes the level of the transmitted signal being generated or at least one step before that level to the level that the transmitting element transmits. Store it as a signal level. In the former case, a value slightly smaller than the storage level is set as the transmission signal level when setting the level, and in the latter case, the storage level is set as the transmission signal level. In this way, the transmission signal level is set in accordance with the installation site and the reflection state of the equipment, and it is possible to eliminate malfunctions such as those caused by the sensor sensing when an object such as a hand is not in the vicinity.

[0010]In addition, in the level changing means, instead of increasing the level of the transmission signal one step at a time, it is lowered one step at a time from the maximum level, and the level at which the receiving element no longer detects the reflected light above the reference level is transmitted. It can also be set as a signal level.

Instead of changing the output level of the transmission signal, it is also possible to change the level of the receiving sensitivity or reference value of the receiving element and set it to an appropriate value.

0012

EXAMPLES The present invention will be specifically explained below based on examples.

FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 4 is a flow chart showing processing in the CPU.

In FIG. 3, 10 is a CPU, 11 is a D/
12 is a drive unit for the transmitting element 1 such as an infrared LED; 13 is a detection unit that amplifies the signal received by the receiving element 2 and compares it with a reference level; and 14 is a level storage unit.

When adjusting the sensitivity during on-site installation, the digital output is changed in steps by the CPU 10, and the D/A converter 11
The signal is converted to an analog level, and the transmission level from the transmitting element 1 is increased in steps via the driving section 12. The receiving element 2 outputs an output signal according to the reflected light, the detection unit 13 reads the sensing level when there is no human hand (non-sensing), and the storage unit 14 stores the level that should not be detected.
It is stored in the CPU 10 and transmitted to the CPU 10 as a transmission level when detecting an actual object. By doing this, the sensing level when a human hand is present is compared with the sensing level when no human hand is detected, and the sensing of a human hand, etc. is performed.

Note that it is of course possible to process the received signal reference level comparison section and level storage section within the CPU.

FIG. 4 shows signal processing during sensitivity adjustment in the CPU 10. When the power is turned on, step 1
00, the initial settings of the CPU 10 are performed. Step 1
At 10, LE indicates that the human body detection sensor is being adjusted.
Turn on D. In step 120, the initial value of variable n is set to zero. In step 130, 1 is added to the variable n. In step 140, an output voltage (or current) of a level corresponding to the number of variables n is output to the transmitting element 1. In step 150, the human body sensing sensor (receiving element 2)
It is determined whether or not the object has been sensed, and if not, the process returns to step 130 and the output level is increased by one step. When an object is sensed in step 150, the previous level of the variable n at that time is stored in step 160. Thereafter, in step 170, the LED during adjustment of the human body detection sensor is turned off. Step 180 causes the variable n to be n
The human body detection sensor is activated with the transmission level at -1.

In this embodiment, when the human body detection sensor detects a human body, the variable n at that time is determined in step 160.
The previous level of is memorized, but this is changed to memorize the level of variable n at that time,
It is also possible to set the output level to a level that is a certain minute level lower than the stored level when the setting switch is manually pressed.

Furthermore, although this embodiment shows an example in which the output level of the transmission signal is automatically changed, it is also possible to automatically change the receiving sensitivity and reference value (threshold value) of the receiving element to set an appropriate value. is also possible.

[0020]Although the above example has been shown in which the present invention is applied to an automatic water faucet, the present invention is not limited to this, and it goes without saying that the present invention can be applied to other object sensing sensors.

[0021]

[Effects of the Invention] As described above, according to the present invention,
Adjustment of the sensing level is automated, and it is also possible to adjust the sensing level according to the situation at the site, allowing for more accurate adjustment.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the principle of a reflective object sensing sensor.

FIG. 2 is an explanatory diagram showing an example of device attachment of an object detection sensor.

FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 4 is a flowchart showing processing in a CPU.

[Explanation of symbols]

1 Transmitting element (light emitting element) 2 Receiving element (light receiving element) 3 Spout 4 Water spout 5. Hand wash basin 6 Ball 10 CPU 11 D/A conversion section 12 Drive section 13 Detection part 14 Memory section

Claims (1)

[Claims] 1. A transmitting element that outputs a transmitted signal, and a receiving element that receives a received signal reflected by an object from among the transmitted signals, and the receiving element has a method for determining the strength of the received signal received by the receiving element and a reference value. In the object sensing sensor that detects the presence of the object based on a comparison of the output level of the transmission signal in the transmission element, the reception sensitivity of the reception signal in the reception element, or the level change that automatically gradually increases or decreases the reference value. and means for holding the output level, reception sensitivity, or reference value when the received signal exceeds or is about to exceed a reference level.