JP2569939Y2 - Illuminance detection sensor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminance detection sensor using a solar cell array. More specifically, the invention can be used as a power supply for a rechargeable battery when the illuminance is detectable in a planar manner and no illuminance is detected. The present invention relates to an illuminance detection sensor that can be used.

[0002]

2. Description of the Related Art Various types of illuminance detection sensors are known. However, all of them detect only when the illuminance is increased or when the illuminance is decreased, and simply determine the magnitude of the detection result. It is configured to output or use the output to control other equipment.

[0003]

However, simply detecting the state of illuminance as in the prior art is a point detection, and it is possible to control devices and elements according to the point detection result. However, for example, when the illuminance distribution is different,
Actually, the illuminance is reduced as a whole, but if the illuminance at the detection point is high, it is determined that the illuminance is high as a whole, and vice versa. In such a case, although the detection accuracy of the illuminance at the detection point is high, appropriate detection is not performed as a whole. Therefore, if the device or the element is controlled according to the detection result, the intended control may not be performed. Further, the illuminance detection means and the power supply means for illuminance detection have completely different configurations, and the cost has been high.

[0004] The present invention has been made in view of such a situation of the prior art. The purpose of the invention is to enable illuminance to be detected two-dimensionally and to perform appropriate control according to the detection state. An object of the present invention is to provide an inexpensive illuminance detection sensor in which illuminance detection means and power supply means for illuminance detection can be configured by the same means.

[0005]

In order to achieve the above object, the present invention provides a solar cell array comprising a plurality of solar cells for generating power according to the amount of incident light, and a method for selecting one solar cell to be measured. A / A for converting the output of the solar cell selected by the selection unit into a digital signal
D conversion means, a rechargeable battery provided with electric power generated by the solar cell when illuminance is not detected, and A / D when illuminance is detected.
While detecting the illuminance by the output from the conversion means,
It is characterized by comprising control means for performing predetermined control on the peripheral elements, and output means for outputting a detection state of illuminance to the outside according to a detection output from the control means.

[0006]

According to the above means, one of the solar cells in the solar cell array is selected by the selection means, and the output of the selected solar cell is converted into a digital signal by the A / D conversion means. And the control means detects the illuminance. The detected illuminance is output to the outside via output means. In this case, the distribution of the illuminance is measured by switching the solar cells to be detected by the selection means and detecting the output of each solar cell. Therefore, it becomes possible to appropriately control devices and elements according to this distribution. When the solar cell is not used for illuminance detection, it can be used as a power supply for the rechargeable battery to continue detection with low power.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of an illuminance detecting sensor according to an embodiment of the present invention. This illuminance detection sensor includes a solar cell array 2 having a plurality of solar cells 1, a multiplexer 3 as selection means for selecting each solar cell 1 of the solar cell array 2, and a solar cell 1 selected by the multiplexer 3. A / D converter 4 for A / D converting the output of
And a central processing unit (hereinafter, referred to as a microcomputer) as a control unit for detecting illuminance from the output of the A / D converter 4 and controlling each element of the circuit.
An output device 6 that outputs an illuminance detection state to the outside in response to a control output from the CPU 5, a rechargeable battery 7 that is charged by supply of power from the solar cell 1,
It mainly comprises an auxiliary battery 8 composed of a lithium battery or the like for supplying electric power when the electric power falls. The output device 6 includes a wireless transmitter 9 and an antenna 10. Other configurations are described in detail below together with these components.

[0008] The solar cell 1 generates electric power by incidence of a light beam. In the illuminance detection state, the generated power is selected from the solar cell array 2 by the multiplexer 3 according to an instruction of the CPU 5, a digital signal is converted by the A / D converter 4, and measured by the CPU 5. In the non-measurement state, the electric power generated by the solar cell 1 is supplied to the rechargeable battery 7. At this time, a diode 9 is provided to prevent the outflow current from the solar cell 1 from flowing into the auxiliary battery 8 and also to prevent the power from the auxiliary battery 8 from flowing into the solar cell 1.

The CPU 5 controls the peripheral elements through a control bus 12, and a timer 13 is provided for controlling an operation mode. The timer 13 determines the operation mode of the CPU 5, and stops when the operation of the CPU 5 is unnecessary, thereby reducing power consumption. Power is supplied from the voltage regulator 14 to the peripheral elements. That is, the voltage regulator 14 is for converting the output voltage from the auxiliary battery 8 or the rechargeable battery 7 to a voltage required for the peripheral elements, and the element to be supplied is selected by the power switch 15. This selection is performed according to an instruction from the CPU 5. The output from the voltage regulator 14 is
CPU 5 and timer 13 which always require voltage supply
, And the other multiplexers 3, A /
A power switch 15 is provided for the D converter 4 and the output device 6.
Power is supplied only when necessary. The output device 6 is a wireless device configured to wirelessly transmit the illuminance detection state, but need not be a wireless device. However, in the case of wireless communication, not only is it convenient to obtain information on a remote place, but also there is an advantage that a wire is not required when a plurality of such devices are operated and a large-scale system can be easily constructed. is there.

The illuminance detection sensor thus configured has a charging period for charging the rechargeable battery and a detection period for detecting the illuminance. First, during the charging period,
The CPU 5 is stopped under the control of the timer 13, and the power switch 15 has not selected any element. Therefore, only the timer 13, the stopped CPU 5, and the voltage regulator 14 consume power. This makes it possible to keep power consumption extremely low. In this state, the electric power generated by the solar cell 1 flows into the rechargeable battery 7 and is stored.

When the CPU 5 is started by the timer 13, the CPU 5 instructs the power switch 15 to supply power to the A / D converter 4, and the power is supplied from the power switch 15 to the A / D converter 4. , A / D converter 4 becomes operable. Further, the CPU 5 instructs the power switch 15 to supply power to the multiplexer 3, and then instructs the solar cell 1 to be measured. The output voltage of the solar cell 1 designated and selected from the solar cell array 2 is converted into a digital signal by the A / D converter 4 and output to the CPU 5, from which the CPU 5 outputs the illuminance of the target solar cell 1. get information. The CPU 5 creates necessary information from the illuminance information, further instructs a required portion of the solar cell 1 to switch the multiplexer 3, and repeats the above operation for the number of measurement points. This makes it possible to obtain necessary illuminance information in a two-dimensional manner. When the CPU 5 obtains the necessary information in this manner, it instructs the power switch 15 to stop supplying power to the multiplexer 3 and the A / D converter 4 and causes the output device 6 to supply power this time. Then
The created information is transferred to the output device 6, and is output wirelessly from the transmitter 9 of the output device 6 via the antenna 10. When this output is completed, the CPU 5 stops the power supply to the output device 6 by the power switch 15, and further stops by the control of the timer 13 until the next start. Then, the above-described charging period starts. In this way, the charging period and the detection period are repeated every predetermined time, and the illuminance is detected.

When the illuminance detection is performed as described above, it is possible to detect the illuminance of the entire periphery on the front side of the solar cell array 2. That is, when an object exists on a certain solar cell 1, the output of the solar cell 1 is smaller than the output of another solar cell 1, so that the existence and the position of the object can be known. When the output of the solar cell 1 is large, it can be understood that light is irradiated to the position of the solar cell 1. Therefore, for example, if this illuminance detection sensor is used for an opening / closing operation switch of an automatic door, the CPU 5 detects that the illuminance of some of the solar cells 1 has changed by holding a hand over a part of the sensor unit. , Can give an instruction signal to open the automatic door. On the other hand, even if the surrounding illuminance decreases due to the sun's shading or the failure of the lighting, etc., since the decrease is detected by all the solar cells 1, the CPU 5 captures the change in illuminance of the entire solar cell 1, but this change is detected. Is not determined as a change due to a hand or the like, and is not detected as a presence of a person due to such a change in illuminance, and does not emit a signal for opening the automatic door. Others
Since the illuminance distribution can be clearly detected, it is possible to accurately grasp the illuminance state at the detection point, and it can also be used for detecting the position of a person moving on the passage.

[0013]

As is clear from the above description, according to the present invention configured as described above, the illuminance is detected from the output of each solar cell using the solar cell array.
By switching and selecting a solar cell to be detected, the illuminance can be detected two-dimensionally, whereby appropriate control according to the detection state can be performed. Further, since a solar cell is used as the illuminance detection means, it is not necessary to configure the illuminance detection means and the power supply means by separate means, and the cost can be reduced accordingly.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an illuminance detection sensor according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solar cell 2 Solar cell array 3 Multiplexer 4 A / D converter 5 CPU 6 Output device 7 Rechargeable battery

Claims (1)

(57) [Scope of request for utility model registration] 1. A solar cell array including a plurality of solar cells that generate electric power in accordance with the amount of incident light, a selection unit for selecting one solar cell to be measured, and a solar cell selected by the selection unit. A / D conversion means for converting an output into a digital signal, a rechargeable battery for storing power generated by a solar cell when illuminance is not detected, and detecting illuminance by output from the A / D conversion means when illuminance is detected. An illuminance detection sensor comprising: control means for performing predetermined control on peripheral elements; and output means for outputting an illuminance detection state to the outside according to a detection output from the control means.