JPH055697B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an automatic wiper device for wiping the windshield of an automobile with a wiper blade.

BACKGROUND ART Typical prior art includes a light path between a light emitting element and a light receiving element that receives light from the light emitting element.
A light receiving element detects that the optical path is blocked by passing rain, snow, etc., integrates the output from this light receiving element, and when the integrated value reaches a predetermined value. The wiper blade is driven by a motor to wipe the windshield of an automobile.

Problems to be Solved by the Invention In such prior art, even if the rainfall condition is constant, raindrops cannot be detected due to the mounting position of the light emitting element and the light receiving element, the size of the raindrop detection range by the optical path, etc. Detection frequency and sensitivity vary. Furthermore, during natural rainfall, the rainfall conditions may change minutely in a short period of time. As a result, in the prior art as described above, the time interval at which the wiper blade is driven varies minutely, which causes discomfort to the driver and the like.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic wiper device that wipes a window or the like with a wiper blade by adjusting the driving time interval of the wiper blade so as to provide a comfortable feeling.

Means for Solving the Problems The present invention comprises: a raindrop detection element for detecting raindrops; an integrating means for integrating the output of the raindrop detection element; a wiper blade for wiping a window, etc.; and a driving means for driving the wiper blade. , a control means that measures the elapsed time from the time when the wiper blade is driven, measures and stores the time interval for each drive, and responds to the integral value from the integrating means to record the elapsed time. comparing time with the time interval and comparing the integral value with a first predetermined value, and when the integral value is less than the first predetermined value when the elapsed time reaches the previous time interval; The process of comparing the integral value after a predetermined time from that point with the first predetermined value is repeated without driving the wiper blade, and when the integral value after the predetermined time is equal to or greater than the first predetermined value, the wiper blade is driven. An automatic wiper device characterized in that it includes control means for driving a wiper blade and resetting an integral value.

In a preferred embodiment, the control means includes:
The integral value is compared with a second predetermined value that is larger than the first predetermined value, and based on the comparison result, the time interval between each drive of the wiper blade is set so as not to change greatly, and the wiper blade is operated by the drive means. It is characterized by driving the blade.

Effect According to the present invention, the control means measures the elapsed time from the time when the wiper blade is driven, and also measures and stores the time interval for each drive, thereby determining the elapsed time. In addition to comparing with the time interval, the integral value obtained by integrating the output from the raindrop detection element by the integrating means is compared with the first predetermined value, and when the integral value has elapsed by the previous time interval, When the integral value is less than the first predetermined value, the process of comparing the integral value after a predetermined time from that point with the first predetermined value is repeated without driving the wiper blade, and the integral value after the predetermined time is determined. When the value exceeds the first predetermined value, the wiper blade is driven by the driving means to wipe the window, etc., and at this time, the integral value is reset.

Therefore, for example, when driving a car in a rainy place, when entering a tunnel, the increase in the integral value becomes extremely slow, and the wiper blade is therefore undesirably driven. This prevents the wiper blade from wiping dry, so that it is comfortable and prevents damage to the window glass and the wiper blade due to dry wiping of the wiper blade.

Embodiment FIG. 1 is a block diagram of one embodiment of the present invention. The raindrop detection element 1 is provided exposed to the outside of the automobile, and includes a light emitting element 2 such as a light emitting diode, and a light receiving element 3 that receives light from the light emitting element 2. When rain, snow, etc. pass through the optical path between the light emitting element 2 and the light receiving element 3, light to the light receiving element 3 is blocked by the raindrops. The light emitting element 2 is driven by a modulation signal from the drive circuit 4. The output from the light receiving element 3 is subjected to envelope detection by the detection circuit 5.

The output waveform derived from the detection circuit 5 to the line 6 is as shown in FIG. 2, and each time a raindrop passes through the optical path of the raindrop detection element 1,
A pulse is obtained. Integrating circuit 7 integrates the detection output from line 6. This integrating circuit 7 delivers an integral output via a line 8 to a processing circuit 9 realized by a microcomputer or the like.

The integral output of the integrating circuit 7 is as shown in FIG. 2, and integrates the pulsed detection output each time a raindrop passes through the optical path. Processing circuit 9
The integral output is level-discriminated using the discrimination level R, and when the integral output becomes equal to or higher than the discrimination level R,
Activate the wiper motor 10. As a result, the wiper motor 10 wipes the windshield, which is a window of an automobile, with the wiper blade 11 in one reciprocation as shown in FIG. 2 and 3. The integration circuit 7 is reset by driving the wiper motor 10. Reference mark T0 in FIG. 2 and 3 indicates the previous time interval each time the wiper blade 11 is driven.

The operation of the processing circuit 9 when the driving time interval of the wiper blade 11 is set to be long will be described. Referring to FIG. 3, when a time equal to the previous time interval T0 has elapsed, the integrating circuit 7
It is assumed that the integral output of has become a value M1 that is less than the second discrimination level R. This value M1 is set to be equal to or higher than the first discrimination level L. That is, the first discrimination level L is smaller than the second discrimination level R. The processing circuit 9 determines the last driving time of the wiper blade 11.
The clocking operation is performed from t1 (see Fig. 2, 3 above),
When a time equal to the previous time interval T0 has passed and the integral value of the integrating circuit 7 is a value M1 that is less than the discrimination level R, the time interval is set based on the value of the integral value M1. That is, as shown in FIG. 4, the previous time interval at which the wiper blade 11 was driven by the wiper motor 10 is indicated by the reference mark T0, and when time T0 has elapsed from time t1, as described above, When the integral value is a value M1 that is less than the discrimination level R, at time t2 when a time ΔTD corresponding to the integral value M1 has further elapsed, the processing circuit 9 activates the wiper motor 10 to activate the wiper blade 11.
is driven by the wiper motor 10.

This time ΔTD is set to a smaller value as the integral value M1 becomes larger, as shown in FIG. Therefore, the difference ΔTD between the previous time interval T0 and the current time interval W1 (=T0+ΔTD) is set small, which is comfortable.

According to the present invention, while driving in the rain, the amount of raindrops detected by the raindrop detection element 1 suddenly changes when entering a tunnel. Even at this time, wiper blade 1
In order to enable the wiper blade 11 to comfortably wipe the window glass without excessively operating the wiper blade 11, the present invention is configured as follows.

Referring to FIG. 6, it is assumed that the integrated value of the integrating circuit 7 gradually increases as time changes, such as when the vehicle enters the tunnel described above. At this time, the processing circuit 9 performs level discrimination on the integral value using the first discrimination level L, which is smaller than the second discrimination level R. Wiper blade 1 by wiper motor 10
When the previous time interval T0 has elapsed since the last time interval T0 has elapsed since the time when 1 was driven back and forth once, it is determined whether the integral value is less than the discrimination level L, and when the integral value is less than the discrimination level L, the first time ΔTA1 Set. It is determined whether the integral value is less than the discrimination level L within this set time ΔTA1, and if the integral value is still less than the discrimination level L at time t01 after the set time ΔTA1 has elapsed, the second Set time ΔTA2, and set this time ΔTA
2, it is determined whether the integral value is less than the discrimination level L. Also at the set time ΔTA2, when the integral value is less than the discrimination level L, a third
Set time ΔTA3. Similarly, at this set time ΔTA3, the integral value is at the discrimination level L.
Determine whether it is less than or equal to. In this embodiment, assuming that the integral value becomes equal to or higher than the discrimination level L at time t4 within the set time ΔTA3, the processing circuit 9 activates the wiper motor 10 at time t03 when the set time ΔTA3 has elapsed. , the wiper blade 11 is driven to wipe the window glass in one reciprocating motion. At the same time, the integral value of the integrating circuit 7 is reset to zero at time t03. Setting time ΔTA
1, ΔTA2, ΔTA3, . . . are determined to become larger values as time elapses after the previous time interval T0 has elapsed, as shown in FIG.
In this way, when driving in the rain and entering a tunnel, the wiper blade does not wipe unnecessarily, making it comfortable and preventing damage to the window glass and wiper blade due to dry wiping. I can do it. Further, the integral value of the integrating circuit 7 reaches the discrimination level R at the time when the time T1, which is less than the time interval T0 of driving the wiper blade 11, has elapsed. At this time, the time interval W2 shown in FIG. 9, which will be described next, is set based on the time interval ΔT (=T0 - T1) from the previous time.

Referring to FIG. 9, the time interval of the previous wiping operation of the wiper blade 11 is T0, and when the time T1 has elapsed from the time t1 when the wiping operation was started, the integral value reaches the discrimination level R as described above. When the time ΔT is reached, the time ΔT is calculated to find the time ΔTu which increases as the time ΔT increases as shown in FIG. This time ΔTu
At time t3, which is subtracted from the previous time interval T0, the processing circuit 9 activates the wiper motor 10 to drive the wiper blade 11. As time ΔT increases, time ΔTu is set to a larger value as described above, and the rate of increase in time ΔTu is small compared to the rate of increase in time ΔT, so time W2 from time t1 to t3 is time interval T0
It is comfortable because it prevents large fluctuations compared to .

The operation of the processing circuit 9 will be explained with reference to FIG. The process moves from step n1 to step n2, and when the power is turned on, initial settings are performed in step n3. In step n4, the integral value M of the integrating circuit 7 is set to zero, and the timer T is set to zero.
At step n5, as raindrops pass through the optical path of the detection element 1, the integral value M increases and the timer T performs a timing operation. In step n6, it is determined whether the time of timer T is greater than or equal to the previous time interval T0, and if not, step n7
Then, it is determined whether the integral value M is equal to or higher than the discrimination level R, and if not, the process moves to step n8, and the time of the timer T is counted.

In step n6, if the time of timer T is greater than or equal to the previous time interval T0, step n9
Then, it is determined whether the integral value is less than the first discrimination level L, and when the integral value M is equal to or higher than the discrimination level L, the process proceeds to step n9c, and in connection with the above-mentioned FIGS. 3 to 5. As mentioned above, the time interval this time is set to be long. That is, in step n9c, it is determined whether the integral value M exceeds the third predetermined value β (L<β<R), and if not, the step
Move to n10 and set the value B1 as ΔTD. Further, when the integral value M exceeds the third predetermined value β in step n9C, a value B2 is determined as the time ΔTD in step n11. Here, B2<B1...(1). In step n12, the process is delayed by time ΔTD, and the time ΔTD, which is the value B1 or B2 set in step n10 or n11, is added to the previous time interval T0 as the current time interval W1. In step n20, the processing circuit 9 activates the wiper motor 10.

At step n9, the integral value M reaches the discrimination level L.
If it is determined that the
Moving to n9a, fixed time B3 is determined as set time ΔTA. The setting time ΔTA1 shown in Fig. 6,
ΔTA2, ΔTA3, ... are collectively indicated by the reference symbol ΔTA. The time B3 is sequentially set to a larger value as time passes, as shown in FIG. 7 described above.
In the next step n9b, the set time ΔTA is added to the previous time interval T0 to create a new time interval T0, and the process moves to step n6. In this way, when the integral value M becomes equal to or higher than the discrimination level L within the set time ΔTA, the step
Moving from step n9 to step n9c, the wiper motor 10 is activated.

In step n7, when the integral value M1 is equal to or higher than the second discrimination level R, the current time interval W2 is set short as shown in FIGS. 6 to 8. That is, in step n13, the difference ΔT between the current time T1 and the previous time interval T0 is calculated. In step n14, this time ΔT
It is determined whether or not exceeds a predetermined value α, and if not, the process moves to step n15, and the time ΔTu is set to a predetermined value A1. If the time ΔT exceeds the value α, the process moves to step n16, and the time ΔTu is set to a predetermined value A2. Here, A2>A1 (2) In step n17, the difference between the time ΔT and the time ΔTu is determined and this value is set as Ta. At step n18, there is a delay of time Ta, and at step n19,
The current time interval W2 is set to a value obtained by subtracting the time ΔTu from the previous time interval T0. step
At n20, the wiper motor 10 is activated by the processing circuit 9. In this way, the time interval W2 is
It will be set to a value close to the previous time interval T0.

FIG. 12 shows a processing circuit 9 according to another embodiment of the present invention.
This is a flowchart explaining the operation. In this embodiment, steps m1 to m8 are similar to steps n1 to n8 in FIG. 11 described above.

In step m6, when the previous time interval T0 has elapsed, the process moves to step m9 and the discrimination level L is set.
When the integral value M is less than the discrimination level L, the process moves to step m10, where the wiper motor 10 is set to operate at a later timing, and the wiper motor 10 moves the wiper blade 11 at a predetermined slower operation timing, i.e. For example, it is driven back and forth every 10 seconds. When the integral value M is greater than or equal to the discrimination level L in step m9, the process moves to step m11, where it is determined whether the integral value M is greater than or equal to the third predetermined value β, and if so, the process proceeds to step m13, where the operation is started. The timing is set as is, and if the integral value M is less than the predetermined value β, the process moves to step m12, where the operation timing is set later and the wiper blade 11 is driven back and forth once at a time interval of 10 seconds. Ru.

In step m7, when the integral value M is equal to or higher than the second discrimination level R, the process moves to step m14, where the same operation as in step n13 in FIG. Compared to the value α, this operation is similar to step n14 described above. In step m16, an operation is performed to advance the operating timing of the wiper blade, for example, an operation is performed in which the wiper blade 11 is driven back and forth once every 5 seconds. step m17
Then, when the time ΔT is greater than or equal to the predetermined value α, the actuation timing is maintained as it is.

The present invention can be widely implemented not only for wiping the windshield of a car but also for wiping other windows etc. with a wiper blade.

In this embodiment, the times ΔTD and ΔTu were set to have a linear relationship with the integral value M and the time ΔT, respectively (see FIGS. 5 and 10).
As other embodiments of the present invention, a stepwise relationship may be provided. For example, in Fig. 5, the integral value M
and ΔTD when X1<M≦X2, ΔTD=Y1, X2<X
When ≦X3, ΔTD=Y2 (however, X1, X2, X3,
(Y1 and Y2 are constant values).

Effects As described above, according to the present invention, when the integral value of the output of the raindrop detection element is less than the first predetermined value, the time interval of driving the wiper blade is changed from that point in time without driving the wiper blade. Repeating the process of comparing the integral value after a predetermined time with the first predetermined value,
When the integral value of the predetermined time exceeds the first predetermined value, the wiper blade is driven by the driving means, so that the time interval between driving the wiper blade can be adjusted to provide a comfortable interval. This makes it possible to prevent the wiper blade from wiping windows etc. dry. Furthermore, even when the rain suddenly stops, the driver can be provided with a comfortable wiper operation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
The figure is a waveform diagram for explaining the operation of this embodiment, FIG. 3 is a diagram showing the relationship between time and integral value M when the discrimination level R is not reached even after the time interval T0 is exceeded, and FIG. FIG. 5 is a diagram showing the relationship between the integral value M and time ΔTD; FIG. 6 is a diagram showing the time course of the integral value when the integral value is small. , Fig. 7 is a diagram showing the relationship between the set times ΔTA1, TA2, TA3, ... and elapsed time, and Fig. 8 is a diagram showing the relationship between the set times ΔTA1, TA2, TA3, ... and the elapsed time.
9 is a diagram showing the drive interval of the wiper motor 10 in the state of FIG. 8, and FIG. 10 is a diagram showing the time in the state of FIG. 8. A diagram showing the relationship between time ΔT and time ΔTu representing the difference between interval T0 and time T1, FIG. 11 is a flowchart for explaining the operation of the above embodiment, and FIG. 12 is another embodiment of the present invention. This is a flowchart for explaining the operation. 1... Raindrop detection element, 4... Drive circuit, 5...
Detection circuit, 7...Integrator circuit, 9...Processing circuit, 1
0...wiper motor, 11... wiper blade.

Claims (1)

[Scope of Claims] 1. A raindrop detection element for detecting raindrops, an integrating means for integrating the output of the raindrop detection element, a wiper blade for wiping a window, etc., a driving means for driving the wiper blade, and a control means. measures the elapsed time from the wiper blade drive time, measures and stores the time interval for each drive, and responds to the integral value from the integrating means, and calculates the elapsed time to the time interval. and comparing the integral value with a first predetermined value, and when the integral value is less than the first predetermined value when the elapsed time reaches a previous time interval, driving the wiper blade. The process of comparing the integral value after a predetermined time from that point with the first predetermined value is repeated without any interruption, and when the integral value after the predetermined time exceeds the first predetermined value, the wiper blade is actuated by the driving means. An automatic wiper device comprising: control means for driving and resetting an integral value. 2. The control means compares the integral value with a second predetermined value that is larger than the first predetermined value, and based on the comparison result, sets the time interval between each drive of the wiper blade so that it does not change significantly. 2. The automatic wiper device according to claim 1, wherein the wiper blade is driven by a driving means.