JPH0690283B2 - Optical detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to, for example, an automatic door opening / closing device that automatically opens and closes a door by detecting that a human body approaches or separates from the door. The present invention relates to an optical detection device used.

[Conventional technology]

The automatic door opening and closing device, the human body has entered the detection area,
In addition, a human body detection device for detecting that a human body has gone out of the detection area is provided, and the door opening / closing drive device is operated by a human body detection signal sent by the human body detection device.
This human body detection device is equipped with a light transmitter and a light receiver, and a light blocking type that detects the human body when the human body blocks the infrared light emitted from the light projector, and receives the reflected light from the human body of the infrared light emitted from the light projector. There is a light-reflecting type that receives light from a container and detects that a human body has entered the detection area.

As a light reflection type optical detection device, there has been a conventional method of 62
-49333 publication. The optical detection device disclosed herein is configured by arranging a first light projecting element array, a second light projecting element array, and a light receiving element array in three upper and lower stages, and the first light projecting element array and the second light projecting element array. The light projecting elements of the light projecting element array are alternately switched and driven. The first light projecting element array forms a fan-shaped front irradiation area that extends in the column direction, the second light projecting element array creates a fan-shaped rear irradiation area that extends in the column direction, and the light receiving element array includes these front irradiation area and rear surface. A front detection area and a rear detection area are created with the irradiation area as the field of view.

[Problems to be solved by the invention]

Since this detection device defines the front detection area and the rear detection area, the detection range in the front-rear direction is expanded as compared with the case where there is only one light emitting element row, but due to the characteristics of the light receiving element, It is difficult to obtain a large light receiving area in the element array.

An optical device for detecting a human body used for an automatic door opening / closing device is installed above the door and, for example, with a width of 2
It is desirable to be able to form a wide detection range of m and depth of 1 m, but this is difficult with the above conventional one, and since the light emitting part and the light receiving part are lined up and down, space is taken in the height direction and the door is closed. There is a problem that it is not suitable as a detection device for an automatic door opening / closing device that is installed in a narrow blind part above, and because the threshold value is set for each light emitting element row unit, the detection accuracy is not very good. From this point as well, there is a problem that it is not suitable for a detection device for an automatic door opening / closing device that needs to detect a human body that has entered the detection area quickly from other objects.

The present invention has been made to solve the above-mentioned conventional problems. The required space in the height direction is small, the detection range can be expanded compared to the conventional one, and the detection speed and detection accuracy can be improved. It is an object of the present invention to provide an optical detection device that can be improved and can reduce power consumption.

[Means for solving problems]

According to the present invention, in order to achieve the above-mentioned object, a light projecting portion is arranged in parallel with a first light projecting element array of light projecting elements arranged in series in a lateral direction. A second light projecting element array is provided, and the light receiving unit is arranged in series with the first light projecting element array and the first light receiving element array of the light receiving elements corresponding to each of the light projecting elements and the second light projecting element array. And a second light receiving element array of light receiving elements corresponding to each of the light projecting elements arranged in series with each of the light projecting element rows of. It is assumed that they are selected and driven cyclically, and the corresponding light-emitting element and light-receiving element share the irradiation area to the floor surface, and the detection area is formed in the part where the irradiation spaces overlap. The device performs signal processing on the output of the light receiving element and outputs the value to the received light. By its magnitude compared to a predetermined value that is set for each detection area corresponding to the child is obtained by configured to determine whether the entry of the human body or object into the detection area.

[Action]

In the present invention, the light projecting element array and the light receiving element array are two rows that are arranged in parallel and extend laterally, and the first light projecting element array, the irradiation area of the first light receiving element array, and the second light projecting element array. A wide detection range in the depth direction can be obtained by the irradiation area of the second light receiving element array. Then, the presence / absence of a human body or an object is dynamically determined for each detection area formed by a pair of a light projecting element and a light receiving element to improve the detection accuracy.

〔Example〕

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

In FIG. 1, A is a light emitting part, B is a light receiving part, 10 is a light emitting element switching switch, 11 is a light receiving element switching switch, 12 is a light receiving signal amplifier, 13 is a sample hold circuit (S / H), The light emitting / receiving device 14 is configured by these.

Reference numeral 20 is a detection control device, which is a micro computer (CP
U) 21, program memory (ROM) 23, data memory (RA
M) 22 interface circuit (PIO) 24 has a detection control section and an A / D conversion section 25. The program memory 23 stores the reference value setting program shown in FIG. 5 and the detection program shown in FIG. 6, as well as an element switching program. Reference numeral 31 is an on-timer, 32 is a relay for creating a door opening / closing command signal, and 33 is a door opening / closing drive device.

As shown in FIG. 2, the light projecting section A comprises a plurality of light projecting elements (light emitting diodes) 1 to 8 arranged in a row on the back of the light projecting lens 9, and the light projecting elements 1 to 8 are arranged. irradiates infrared rays R on the floor surface toward the optical axis to the floor surface F of the door front, as shown in FIG. 3 (a) and (b), the irradiation area consisting classified irradiated region C ₁ -C ₈ It defines C toward the floor F. The group of the light projecting elements 5 to 8 forming the second light projecting element array shares the door-side half of the irradiation area C (referred to as the second half of the irradiation area), and forms the first light projecting element array. The optical elements 1 to 4 share the first half of the irradiation area C (the first half of the irradiation area). Light-receiving unit B, as shown in FIG. 2, the light receiving lens 9A back to the light receiving element 1A~8A the horizontal toward the center on the floor of the respective light segment illuminated zone an axis C ₁ -C ₈ 2 It is arranged collectively in rows, and each of the light emitting elements 1 to
Figure 3 (a) to the irradiation space by 8, to form a (b) are shown by hatching detection area S ₁ to S ₈ (however, S ₅ to S ₇ are not shown).

The light projecting elements 1 to 8 receive a drive signal (frequency of 1 KHz to 2 KHz) via the light projecting element switching switch 10 and repeatedly emit infrared rays R having a pulse waveform as shown in FIG. 4 (a). Light receiving signals (shown in FIG. 4 (b)) V _L sent by the light receiving elements 1A to 8A
Is taken out through the light receiving element switching switch 11 and the amplifier 12
The signal is amplified by and then input to the sample hold circuit 13. The light emitting element switching switch 10 receives the switching signal Sw and inputs the drive signal P to the light emitting elements 1 to 8 in this order cyclically and at high speed, and the light receiving element switching switch 11 receives the switching signal Sw and receives light. The elements 1A to 8A are switched and connected to the amplifier 12 in synchronization with the switching of the light projecting elements 1 to 8 respectively. The sample-hold circuit 13 receives the sample-hold signal S / H and receives the received light signal (pulse signal) V
Sample and hold the maximum level V _{LMAX of L.}
The A / D converter 25 uses the hold value V of the sample and hold circuit 13.
Convert _LMAX to digital value and input to CPU21. The drive signal P, the switching signal Sw, and the sample hold signal S / H are C when the power switch (not shown) is turned on.
It is sent from the PU 21 and supplied to the light projecting / receiving device 14 through the interface circuit 24.

Next, the operation of this device will be described.

When the above power switch is turned on, the CPU2 of the detection control device 20
1, the light projecting elements 1 to 8 are switched at predetermined time intervals to emit infrared rays R, and the light receivers 1A to 8A are driven in synchronization with the light projecting elements 1 to 8 to detect the detection area S ₁ to. Receives the reflected light RL from S ₈ and receives it at a level proportional to the amount of reflected light.
Send V _L sequentially. Hereinafter, for convenience of description, the detection area S ₁ set by the set of the light projecting element 1 and the light receiving element 1A that are driven in synchronization will be described.

1 Reference Value Setting Operation (Refer to Reference Value Setting Program) First, when the power is turned on, execution of the reference value setting program is automatically started. This program is executed in an environment where no human is present in the detection area S ₁ . The A / D converter 25 uses the first pulse, the second pulse, ... The nth pulse (where n = 4 in this example) of the light receiving signal V _L sequentially sent from the light receiving element 1A. ) Maximum level value VLM
AX is converted to a digital value and sent to CPU21. When the maximum level value V _LMAX of the nth pulse is digitally converted, the CPU 21 calculates an average value N ₁₀ of the n digital values D ₀₁ , D ₀₂ , ... D _0n , and the average value N ₁₀ With thresholds σ _u and σ _d above and below the detection area S _{1 as} the reference value,
Set K ₁ (N ₁₀ −σ _d <K ₁ <N ₁₀ −σ _u ) and store it in the data memory 22 detection area S ₁ address. This reference value setting routine is similarly executed for the detection areas S _{2 to} S ₈ ,
Each criterion K _{2 to} K ₈ is set.

II Detection Operation (Refer to Detection Program) After the reference value setting operation is completed, the detection program of FIG. 6 is sequentially executed for the detection areas S _{1 to} S ₈ . The detection area S ₁ will be described below.

The A / D converter 25 converts the maximum level value V _LMAX of the pulse of the received light signal V _L into a digital value, as in the reference value setting operation, and the CPU 21 converts the maximum level of n (n = 4) pulses. When the value is digitally converted, n (n = 4) digital values
The average received light amount N ₁₁ is calculated by averaging D ₁₁ , D ₁₂ , ... D _1n , and it is determined whether the average received light amount N ₁₁ is outside the criterion K ₁ . When it is within the determination standard K ₁ , the average light receiving amount calculation operation is repeated on condition that the relay 32 is deenergized and the door opening / closing command signal Y disappears.

When the average received light amount N ₁₁ is outside the criterion K _1, in order to confirm whether the average received light amount N ₁₁ is affected by disturbance such as sunlight or instantaneous flying objects, The detection routine similar to is repeated. That is, the CPU 21 averages the digital values of the subsequent 2n (n = 4) pulses to calculate the average received light amount N ₁₂ . In this case, abnormally large or small digital values are excluded as those due to the disturbance or AC component, and the remaining digital values are averaged. Next, it is determined again whether or not this average received light amount N ₁₂ is outside the criterion K _1, and if it is still outside the criterion K _1, it is necessary to confirm whether or not it is affected by ambient light. , The third detection routine is repeated, and the CPU21
Calculates the average received light amount N ₁₃ by averaging the digital values of the subsequent 2n (n = 4) pulses. Also in this case, the abnormally large or small digital value is excluded, and the remaining digital values are averaged. The CPU 21 uses this average received light amount N ₁₃ as the average received light amount N ₁₂ obtained in the second detection routine.
If they match or approximate to each other,
It judges that a person has entered the detection area S ₁ and sends the human body detection signal X to the relay 32. As a result, the relay 32 is energized (turned on).

As described above, in this embodiment, the first light projecting / receiving element rows 1A to 4A for setting the detection areas S _{1 to} S ₄ in the irradiation areas of the first light projecting element rows 1 to 4 and the second light projecting element rows 1A to 4A. is provided with the second light emitting and receiving element arrays 5A~8A to set the detection area S ₅ to S ₈ to the irradiating region of the element array 5-8, the first light projecting element arrays and the second light projecting element arrays On the other hand, the detection range in the depth direction can be expanded as compared with the conventional one having a common light receiving element array.

Further, since the light projecting section A and the light receiving section B are arranged side by side,
The required space in the height direction can be reduced.

Further, since each of the light projecting elements 1 to 8 and each of the light receiving elements 1A to 8A are cyclically driven, power consumption can be saved.

Further, although a large number of light emitting elements and light receiving elements are used, the light emitting elements and the light receiving elements are made to correspond one-to-one to sequentially define detection areas, and a determination standard is set for each detection area. Therefore, it is possible to improve the detection speed and the detection accuracy as compared with the conventional case where the threshold value is set for each light emitting element array unit.

Further, in this embodiment, since human body detection is performed by software, there is an advantage that the configuration of the device is simplified.

〔The invention's effect〕

According to the present invention, as described above, the first light receiving element row is arranged side by side with respect to the first light emitting element row, and the second light receiving element row is arranged side by side with respect to the second light emitting element row. Due to
The required height of the device can be reduced and the depth of the detection range can be expanded compared to the conventional one, and the human body or the dynamic area can be dynamically set for each detection area formed by a pair of a light emitting element and a light receiving element. Since the presence / absence of an object is determined, the detection speed and the detection accuracy can be increased, so a wide detection range is required,
It is extremely suitable for an automatic door opening / closing device that needs to detect a human body separately from other objects.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing an arrangement configuration of a light projecting element and a light receiving element in the above embodiment, and FIGS. 3 (a) and 3 (b) are detection areas. FIG. 4 (a) is an output waveform diagram of the projector in the above embodiment, FIG. 4 (b) is an output waveform diagram of the light receiver in the above embodiment, and FIG. 5 is a reference value setting program in the above embodiment. 6 is a flow chart of the detection program in the above embodiment. 1-8 ... Emitter element, 1A-8A ... Receiving element, 10 ... Emitter switching switch, 11 ... Receiving element switch, 20 ...
… Detection control device, 21 …… CPU.

Claims (1)

[Claims] 1. A light projecting device comprising a first light projecting device array of light projecting devices arranged in series in a lateral direction and a second light projecting device array arranged in parallel with the first light projecting device array. And a first light-receiving element array of the light-receiving element arranged in series with the first light-projecting element array and corresponding to each of the light-projecting elements and the second light-projecting element array in series. And a detection control device for cyclically selecting the corresponding pairs of the light-projecting element and the light-receiving element to drive them in a cyclic manner. The light emitting element and the light receiving element share the irradiation area to the floor surface, and the detection area is formed in a portion where the irradiation spaces overlap, and the detection control device processes the output of the light receiving element. The value is set to the predetermined value set for each detection area corresponding to the light receiving element. An optical detection device characterized in that the presence or absence of a human body or an object entering the detection area is determined based on the size of the comparison.