Power Window Control Apparatus

The present invention relates to a power window control apparatus.

Electronic power window mechanisms for opening/closing window glass with switching operation have been recently preferred. Demand has arisen for modifying a manual window mechanism to a power window mechanism. For this purpose, a window glass opening/closing motor is mounted and electric wires are connected between the motor and switches arranged on a door.

In order to control motor rotational directions, five wires including the power supply lines and control lines must be connected. These wires are thick and cannot be fitted in conventional doors. The wires run inside the vehicle compartment, resulting in poor appearance.

The switch for opening/closing the window is normally mounted on the arm rest. When a child rides at the window side, he or she touches the switch and the window is accidentally closed. The child may get hurt when he or she is sandwiched between the window glass and the window frame. Under these circumstances, the switches must be concentrated and arranged at the center of the compartment.

For this reason, only the power supply wires can be connected to the motor, and a control unit can be arranged substantially at the center of the compartment to control the rotational direction of the motor. However, in order to separately open/close the front and rear windows, eight switches are required. It is difficult to arrange such a large number of switches in the narrow compartment. When the number of switches is increased, the operation becomes cumbersome, resulting in inconvenience.

Demand has arisen for a compact power window control apparatus which is simply operated and safe without operation errors.

It is an object of the present invention to provide a power window control apparatus which does not require a large mounting space and can be easily and safely operated.

In order to achieve the above object of the present invention, there is provided a power window control apparatus comprising a transmitter, detachably mounted to a fixed member in a compartment, for transmitting coded infrared ray signals corresponding to opening/closing operations of right and left windows of a vehicle and a receiver fixed in the compartment, said receiver being provided with a photosensor for receiving a transmission signal from the transmitter, an amplifier, a detector, a decoder for decoding a signal detected by the detector and generating an output signal corresponding to a content of the detected signal, a relay circuit, opening/closing contacts thereof upon generation of the output from the decoder, for controlling rotation of window opening/closing drive motors, a manual switch for driving the relay circuit independently of the signal from the transmitter, a reset circuit for resetting the decoder for a predetermined period of time after an ignition switch is turned on, and a braking circuit for braking a corresponding one of the motors when a driver releases a transmitter or receiver switch.

FIGS. 1 and 2 are circuit diagrams of a transmitter and a receiver in a power window control apparatus according to an embodiment of the present invention, respectively;

FIG. 3 is a partially cutaway perspective view of the receiver;

FIG. 4 is a plan view of the transmitter;

FIG. 5 is a sectional view of the transmitter;

FIG. 6 is a perspective view showing the positional relationship between a holder and the transmitter mounted in the holder;

FIG. 7 is a sectional view of the holder;

FIG. 8 is a circuit diagram of a reset circuit;

FIGS. 9 and 10 are circuit diagrams of a transmitter and a receiver in a power window control apparatus according to another embodiment of the present invention, respectively;

FIGS. 11 and 13 are respectively circuit diagrams of arrangements for decreasing a transmitting output in specific cases;

FIG. 12 is a diagram showing an infrared ray from a light-emitting diode; and

FIG. 14 is a circuit diagram showing an arrangement of the receiver for decreasing a receiving sensitivity in a specific case.

FIGS. 1 and 2 show a power window control apparatus according to an embodiment of the present invention, in which FIG. 1 is a circuit diagram of a transmitter thereof and FIG. 2 is a circuit diagram of a receiver. Referring to FIG. 1, reference numeral 1 denotes a battery; 2, a transmitting unit; 3a, 3b, 3c and 3d, switches for opening/closing side door windows, respectively; 4a, an infrared ray light-emitting diode; 5, a transmission indicator light-emitting diode; 6a and 6b, transistors, respectively; 7, a diode; 8, a capacitor; and 9a and 9b, resistors, respectively. The transmitting unit 2 generates a code signal corresponding to an operated one of the switches 3a to 3d from a terminal 2a. The switch 3a is used to open the left door glass window, the switch 3b is used to close the left door glass window, the switch 3c is used to open the right door glass window, and the switch 3d is used to close the right door glass window.

Referring to FIG. 2, reference numeral 10 denotes a relay; 10a to 10d, contacts of the relay 10, respectively; 11, a transistor; 12b to 12e, diodes, respectively; 13c, 13d and 13e, resistors, respectively; and 15a and 15b, switches, respectively. The relay 10, the transistor 11, the diodes 12b to 12e, the resistors 13c, 13d and 13e, and the switches 15a and 15b constitute a switching circuit for switching for the front and rear door glass window opening/closing control signals. Reference numeral 20 denotes a constant voltage circuit; 21, a light-receiving photodiode; 22, an amplifier; 23, a detector; 24, a decoder; 25, a reset circuit; 26a to 26g, inverters, respectively; 27, 28, 29, 30, 31, 32, 33 and 34, relays, respectively; and 27a, 28a, 29a, 30a, 31a, 32a, 33a and 34a contacts of the relays 27 to 34. Reference numerals 35 to 38 denote motors. The motor 35 is used to open/close the rear left door glass window, the motor 36 is used to open/close the rear right door glass window, the motor 37 is used to open/close the front left door glass window, and the motor 38 is used to open/close the front right door glass window. When the signal supplied from the detector 23 represents opening of the left door glass window, the decoder 24 generates a signal of logic "1" at a terminal 24a thereof. However, when the signal from the detector 23 represents closing of the left door glass window, the decoder 24 generates a signal of logic "1" at a terminal 24b thereof. When the signal represents opening of the right door glass window, the decoder 24 generates a signal of logic "1" at a terminal 24c thereof. When the signal represents closing of the right door glass window, the decoder 24 generates a signal of logic "1" at a terminal 24d thereof. A terminal 24e will be described later.

FIG. 3 is a perspective view of a receiver R mounted on a dash board or the like. Referring to FIG. 3, buttons 15A and 15B are depressed to turn on the switches 15a and 15b, respectively. The buttons 15A and 15B are normally housed in recesses and cannot be accidentally touched. Reference numeral 40 denotes an infrared filter. Reference numeral 21 denotes an infrared ray sensor fixed on a printed circuit board 100 in the infrared filter 40. Reference numeral 41 denotes a mounting bracket.

FIG. 4 is a plan view of a transmitter T, and FIG. 5 is a sectional view thereof taken along the line V--V of FIG. 4. In the transmitter T, a reed switch 3e is arranged in a position corresponding to a magnet 54 of a holder H.

FIG. 6 shows the holder H mounted on a rear console or the like located between the driver's seat and the front passenger's seat and the transmitter T housed in the holder H. The transmitter T has a mounting groove 50 in a side surface along the longitudinal direction thereof and a positioning groove 51 along a direction of thickness thereof. The groove 50 can engage with an engaging member 52 of the holder H, and the groove 51 can engage with a positioning projection 53, thereby fixing the transmitter T in the holder H. Reference numeral 101 denotes an infrared lens.

FIG. 7 is a sectional view of the holder H. Referring to FIG. 7, reference numeral 54 denotes a magnet.

The operation of the power window control apparatus having the arrangement described above will be described hereinafter.

When the ignition switch IG is turned on, a voltage is supplied from a power supply B to the decoder 24 through the constant voltage circuit 20. An input voltage is applied to the reset circuit 25. The reset circuit 25 resets the decoder for a predetermined period of time determined by an RC circuit so as to reset the decoder 24 to the initial state, thereby preventing a power ON error. An arrangement of the reset circuit 25 is illustrated in FIG. 8. Referring to FIG. 8, the constant voltage is supplied from the constant voltage circuit 20 to a terminal T18 and a time constant circuit consisting of a capacitor 25a and a resistor 25c of the reset circuit 25. As a result, a transistor 25f keeps ON state for a time interval determined by the capacitance of the capacitor 25a and the resistance of the resistor 25c. For this time interval, a terminal T17 of the decoder 24 is held in "L" level, thereby resetting the decoder 24 and preventing an operation error of the receiver upon energization of the apparatus.

When the transmitter T is mounted in the holder H, the reed switch 3e of the transmitter T is kept on by the magnet 54 of the holder H. In this state, when the driver depresses the switch 3a of the transmitter T to move the left door glass window downward, a code signal representing the ON state of the reed switch 3e and corresponding to the function of the switch 3a appears at the terminal 2a of the transmitting unit 2. The infrared ray is emitted from the light-emitting diode 4a in response to the code signal. The infrared ray is received by the photodiode 21 in the receiver R and converted to an electrical signal.

The electrical signal from the photodiode 21 is amplified by the amplifier 22. The amplified signal is detected by the detector 23, and the detected signal is supplied to the decoder 24. In this case, the transmitted signal represents opening of the left door glass window. At the same time, the reed switch 3e is kept on. The signal of logic "1" appears at the terminals 24a and 24e of the decoder 24. As a result, the signal appearing at the terminal 24e triggers the transistor 11 which then energizes the relay 10. The contacts 10a to 10d of the relay 10 are switched in the positions opposite to those illustrated in FIG. 2. The signal appearing at the terminal 24a drives the relay 31 through the inverter 26d, so that the motor 37 is rotated to open the front left door glass window.

When the switch 3b of the transmitter T is depressed to close the front left door glass window, a detection signal appears at the terminal 24b of the decoder 24 to drive the relay 32. The motor 37 is rotated in the reverse direction to close the front left door glass window. Similarly, when the switch 3c of the transmitter T is depressed, the relay 33 is driven to open the front right door glass window. When the switch 3d is depressed, the relay 34 is driven to close the front right door glass window.

When the transmitter T is removed from the holder H, the reed switch 3e is turned off. In this state, when a switch of the transmitter T is depressed, the signal of logic "1" does not appear at the terminal 24e of the decoder. The relay 10 is not energized. The signals appearing at the terminals 24a to 24d drive the relays 27 to 30, respectively, to rotate the motor 35 or 36, so that glass window opening/closing control of the rear doors is started. In this case, the switch 15a or 15b is operated, the relay 10 is turned on, and the contacts 10a to 10d are set in positions opposite to those illustrated in FIG. 2. The signal of the operated switch is supplied to the output of the detector 23 through the inverter 26a to block the output signal of the detector 23. Therefore, the signal from the transmitter T will not be received. For this reason, the front door glass window control wherein the driver operates the switch 15a or 15b has a priority over the control of the transmitter T. The signal generated through the inverter 26b or 26c drives the relay 33 or 34. The front right door window, i.e., the driver's seat glass window can be opened/closed irrespective of the operation of the transmitter T.

The transmitter T has a transmission indicator light-emitting diode 5. When any one of the switches 3a to 3d is depressed, the diode 5 is turned on. For this reason, when the driver visually checks the ON/OFF state of the diode 5, he can check whether the transmitter T is normally operated.

In such an apparatus, when the battery is almost dead, the transmitting output is decreased. In this case, when the transmitter is located near the receiver, the transmitter can be properly operated. For this reason, the transmitter must be removed from the holder. Even in this state, the nonlocking pushbutton can be arranged in parallel with the reed switch 3e to perform the opening/closing control of the front door glass windows. The transmitter can be used without paying attention to the current position of the switch.

In operation, when the depressed switch in the transmitter is released during upward or downward movement of the glass window, the infrared ray is not generated. The operated ones of the relays 27 to 34 restore the state shown in FIG. 2. As a result, the operated motors are braked and immediately stopped.

According to the above embodiment, the front and rear seat passengers can easily remote control opening/closing of the glass windows with the transmitter T. In addition, the front glass windows can be opened or closed by the switches 15a and 15b in the receiver R irrespective of the operation of the transmitter T. In the conventional power window mechanism, a total of three wires is required for the power source and control lines. These lines are powered with a large current and must therefore be thick. These thick lines cannot be easily installed in the doors. However, according to the present invention, only the power source lines are connected to the motor, so that the wires can be easily installed in the door. Furthermore, a space for switch installation can be minimized.

Furthermore, the decoder 24 in the receiver R is reset after the ignition switch is turned on, thereby guaranteeing stable operation.

Furthermore, since the receiver R is operated only after the ignition switch is turned on, the windows cannot be opened or closed by another transmitter of the same type. Therefore, theft and other pranks can be completely prevented.

The controller for opening or closing the glass window is arranged substantially at the center of the compartment. Even if a child accidentally operates the switch, he will not be sandwiched between the window glass and the window frame.

Furthermore, when the operator releases a finger from the operated switch for opening/closing glass window, the corresponding motor is braked and stopped, thereby guaranteeing safe operation.

FIGS. 9 and 10 are circuit diagrams showing a transmitter T and a receiver R, respectively, in a power window control apparatus according to another embodiment of the present invention. In this embodiment, the transmitter T can be detachably attached to the receiver R. A reed switch 14 is arranged in the receiver R. When the transmitter T is attached to the receiver R, the reed switch 14 is turned on by a magnet in the transmitter which is located opposite to the reed switch 14. By attachment/detachment of the transmitter, control operations for the front and rear windows can be switched. More specifically, when the transmitter T is mounted on the receiver R, a light-emitting diode 4b mounted facing down transmits an infrared signal to the receiver R.

One of the most important issues in the power window control apparatus in the vehicle is to prevent an accident of a child being sandwiched between the window glass and the window frame when he accidentally operates the transmitter.

FIG. 11 is a circuit diagram showing another arrangement of the transmitter in consideration of an accident prevention function.

Referring to FIG. 11, a control signal corresponding to a control item associated with opening/closing of the window is generated from a terminal 60a of a transmitting output control circuit 60 in the transmitter T. The terminal 60a is connected to the base of a transistor 71 in a transmitting output power reduction circuit 70 through a resistor 73. The collector of the transistor 71 is connected to the light-emitting diode 4a through a resistor 76.

The control circuit 60 also has terminals 60b and 60c. The terminal 60c is connected to the collector of the transistor 61 and to the base thereof through the resistor 63. The collector of the transistor 61 is also connected to the terminal 60b through a diode 62. The terminal 60b is connected to the base of a transistor 72 through diodes 77 and 78 which are reverse biased with each other. A common junction between the diodes 77 and 78 is connected to the terminal 60a through a resistor 74. The collector of the transistor 72 is connected to the light-emitting diode 4a through a resistor 75. The terminal 60c of the transmitting output control circuit 60 is connected to a power supply 1 through the switch 70.

The switch 70 is turned on when a specific signal, e.g., a control signal for moving the window downward is generated from the light-emitting diode 4a. For example, when the switch 3a or 3c is depressed as in the previous embodiment, the switch 70 is turned on. When the switch 70 is turned on, the transistor 61 is turned on, so that a signal of "L" level is generated from the terminal 60b through the diode 62.

When a window is to be opened, the switch 70 is kept off, and the terminal 60b is kept at "H" level. In this case, the transistor 72 is turned on/off together with the transistor 76. A current flowing in the light-emitting diode 4a is determined by resistances of the resistors 75 and 76. When the resistance of the resistor 75 is set to be sufficiently smaller than that of the resistor 76, a current flowing through the light-emitting diode 4a is substantially controlled by the resistor 75. Infrared output energy for opening the window is high.

When specific control, e.g., window closing control is to be performed, the switch 70 is turned on, and the terminal 60b of the transmitting output control circuit 60 is set at "L" level. The transistor 72 is turned off. In this case, a current flowing through the light-emitting diode 4a is determined by the resistance of the resistor 76. Therefore, infrared output energy can be decreased.

The infrared ray emitted from the light-emitting diode 4a has directivity indicated by the broken line of FIG. 12. For this reason, in order to close the glass window, the infrared energy is determined such that the infrared ray is received by the photodiode (not shown) only when a major optical axis A of the diode 4a is directed to the photodiode, and that the infrared ray emitted from any direction can be received in other control operations. The window glass closing control is invalid when the infrared ray is accidentally emitted in a direction except for the photodiode direction, thereby guaranteeing safe operation.

FIG. 13 is a circuit diagram showing another arrangement for reducing the transmitting output. The same reference numerals as in FIG. 13 denote the same parts as in FIG. 11. In the same manner as the circuit of FIG. 11, in order to open the glass window, resistances of resistors 75 and 76 are determined such that a large current flows in an infrared light-emitting diode 4a when transistors 71 and 72 are turned on, and that a small current flows in the light-emitting diode 4a during window glass closing control. Reference numeral 84 denotes a diode.

The specific control operation is exemplified by the window glass closing control operation. However, this control operation may be replaced with a control operation for opening/closing the driver's seat glass window. In this case, the photodiode is arranged near the dashboard. For specific control, infrared energy can be determined such that the infrared ray emitted from the driver's seat can be detected by the photodiode but the infrared ray emitted away from the driver's seat cannot be detected.

In the above embodiment, infrared ray energy is decreased for specific control. Even if specific control is accidentally performed, the control operation will not be valid. When specific control is important, an accidental operation will not cause an unexpected accident, thereby guaranteeing safe operation.

FIG. 14 shows an arrangement of a receiver R in consideration of a child accident prevention function. The same reference numerals in FIG. 14 denote the same components as in FIG. 2.

In the receiver R, a detector 23 has a transformer 23a connected to an output of an amplifier 22. A capacitor 23b is connected to two ends of the secondary winding of the transformer 23a. The center tap of the secondary winding is connected to the input of a diode 23d. A capacitor 23c and a resistor 23e are connected in parallel with each other between the output terminal of the diode 23d and ground. The output terminal of the diode 23d is connected to the noninverting input terminal (+) of an operational amplifier 23j through a resistor 23h. The inverting input terminal (-) of the operational amplifier 23j is connected to an output terminal T10 of the decoder 24 through a resistor 23i. The operational amplifier 23j constitutes a comparator which compares the noninverted input signal with the inverted input signal and which generates an output representing a difference between the noninverted and inverted input signals. The output from the comparator 23j is supplied together with the output from the inverter 26a to a terminal 16 of the decoder 24.

A level shift signal appears at the output terminal T10 while the specific signal, e.g., the control signal for closing the window glass is received at the terminal T16 of the decoder 24. The level of the level shift signal is set to cause the comparator 23j to detect a signal received at the noninverting input terminal thereof only when the axis (A in FIG. 12) of the infrared ray emitted from the light-emitting diode 4a in the transmitter T is located near the center of the reception beam of a photodiode 21. The operation of the power window control apparatus having the arrangement described above will be described hereinafter.

When the switch 3a or 3c (FIG. 1) in the transmitter T is depressed to open the window glass, a code signal corresponding to the function of the depressed switch is generated from the light-emitting diode 4a and is received by the photodiode 21 in the receiver R. An electrical signal from the photodiode 21 is amplified by an amplifier 22. The amplified signal is supplied to the noninverting input terminal of the comparator 23j in the detector 23. Since this input signal does not represent a specific control signal (e.g., a signal representing closing of the window), the terminal T10 of the decoder 24 is kept at "L" level. When the detection level of the comparator 23j is determined such that the resistances of the resistors 23f, 23g and 23i maximize the receiver sensitivity, the reception signal can be determined even if the central direction A of the beam from the light-emitting diode 4a is not directed toward the receiver R, i.e., even if the reception input level is low.

When the switch 3b or 3d in the transmitter T is depressed to close the window, the control signal is the specific signal. In this case, the signal having the predetermined level as described above is generated from the terminal T10 of the decoder 24. As a result, the detection level of the comparator 23j is increased. Only when the center of the infrared ray from the light-emitting diode 4a is accurately directed toward the photodiode 21 in the receiver R, the input can be detected. When the same subsequent signal is received from the transmitter, the signal of "H" level from the output terminal T4 or T6 of the decoder 24 causes the motor to rotate so as to close the window. When the transmitter T is operated to close the window glass, the transmitter is operated while it is accurately directed toward the receiver, thereby closing the window glass. However, when a child accidentally plays with the transmitter T, the infrared ray from the transmitter T is not accurately directed toward the receiver R. In this manner, the window is not closed, thereby guaranteeing safe operation.

The above operation is neglected when the driver operates the switch 15a or 15b to open/close the driver's seat window glass since the "L" level signal is supplied from the inverter 26a to the terminal T16 of the decoder 24.

Various combinations of circuit arrangements, structures and mounting modes of the transmitter T and the receiver R in each embodiment described above can be proposed.

Since the infrared ray has strong directivity and large attenuation, no interference will be effected by electromagnetic induction or the like. Therefore, the infrared signal can be optimally used for a vehicle transmitter T.