JP2602543Y2 - Remote control unit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control unit which can be operated continuously even after detecting a dead battery in various infrared remote control units using a battery as a power supply.

[0002]

2. Description of the Related Art In recent years, an infrared remote control unit using infrared rays has been used in various places, and since a battery is used as a power supply, the battery voltage is lowered after long-term use and the device does not operate. There is no problem if it simply does not operate, but most of the recent infrared remote control devices use the CPU 1 as shown in FIG. However, the CPU has a minimum operating voltage for normal operation, and malfunction may occur if the voltage is lower than the minimum operating voltage. For this reason, when the CPU reset voltage detection circuit 5 detects that a predetermined value has been interrupted as a result of a drop in the power supply voltage, the CPU 1 is reset to at least prevent malfunction. However, in recent years, the value added of products has been increased, and therefore, remote controllers equipped with memories such as learning remote controllers, clocks, and timers have been increasing. When a remote controller having a memory function is used, if the reset is suddenly performed when the voltage drops, the memory contents are reset, and the stored contents of the timer and the like are lost.

For this reason, when the switch 4 is operated and remote control light emission from the infrared light emitting element 5 is performed, it is detected by the battery exhaustion detection circuit 2 that the battery exhaustion is approaching before the CPU 1 is reset. When this detection is performed, a method of immediately stopping remote control light emission so as not to lower the voltage further is adopted. By stopping the remote control light emission, the transient voltage drop of the battery 6 due to the light emission stops, and the voltage returns, so that it is not detected that the voltage has dropped below a predetermined value, and the CPU 1 is not reset. If necessary, the battery runs out.
To be displayed. These circuits reduce the voltage of the battery 6 to 3
V, if the minimum operating voltage of the CPU 1 is about 2 V, the battery exhaustion detection voltage is set to about 2.3 V, and the CPU reset detection voltage is set to about 2.1 V.

[0004] FIG. 6 is a time chart thereof, in which (a)
When the switch 4 is operated as shown in, for emitting the infrared light emitting device 5 in response to the signal code transmission as shown in (b). The code signal transmitted at this time has a code transmission period of about 100 ms as shown in FIG. 7, and the same code signal is repeatedly transmitted several times during the switch operation to ensure reliability.

[0005] During the voltage of the battery 6 is high enough as shown in the left part of (c), although less voltage drop during transmission, increasing the internal resistance of the batteries 6 cell 6 comes exhausted, transmission the start when the power supply voltage is lower immediately lower <br/> as shown in the middle part of (c). When detecting that the power supply voltage has dropped below the set voltage V1, the battery exhaustion detection circuit 2 sends a battery exhaustion detection signal as shown in FIG. This gives C
Since the PU 1 stops driving the infrared light emitting element 5, the light emission stops. At this time, a battery exhaustion notice is displayed on the liquid crystal display element 7 as shown in FIG. Furthermore, the consumption of the battery 6 progresses,
When the CPU reset voltage detection circuit 3 detects that the power supply voltage has dropped below the set voltage V2 (V2 <V1) , a CPU reset signal is generated as shown in (e) , so that the CPU 1 is reset. Note that the detection voltage V2 of the CPU reset voltage detection circuit 3 is equal to CP as described above.
It is set slightly higher than the minimum operating voltage of U1.

[0006]

As described above, the CPU 1 is reset before reaching the minimum operating voltage, so that the CPU 1 does not malfunction. However, since the light emission stops halfway, it becomes information that a certain switch has been pressed. sell information, for example, all 1 transmission period of the code signal shown in FIG. 7 will not be able to send,
The contents of the memory will not be erased, but the original functions of the remote control will not be able to be exhibited. In this case, there is no problem if the batteries can be replaced immediately, but AAA batteries are often used to make the remote control thin, but this battery is often not available unless it is limited. Exchange is not possible immediately. In such a case, there is a problem that even if there is a request to use the remote controller even temporarily, the request cannot be met. The present invention has been made in view of such a situation, and makes it possible to use a remote controller as soon as possible even when a dead battery is detected.

[0007]

In order to solve such a problem, the present invention monitors a battery voltage as an operation power supply,
When detecting that the battery voltage has dropped to the battery exhaustion detection voltage set to a value higher than the minimum operating voltage of the CPU, the code signal being transmitted is immediately interrupted without interrupting the code signal.
Sending is continued until the transmission period is completed and then interrupted
Disconnection means, reset means for resetting the CPU when the time when the battery exhaustion detection voltage has become equal to or less than the predetermined value continues for a predetermined value or more , and a code signal being transmitted by the transmission interruption means.
At a predetermined time after being suspended after the completion of one code transmission period
Until the time has elapsed, disable the next switch operation.
And a step .

[0008]

When the battery voltage falls below a predetermined value by the dead battery detection circuit , the code signal being transmitted is output.
It is not interrupted immediately and continues until one code transmission period is completed.
Is interrupted after continuing, that is, after transmitting one code signal
You. Also, the battery voltage is the set value (battery exhaustion detection voltage)
When the time to become less than or equal to the predetermined time
Is reset. Also, if the code signal being transmitted is one
After the transmission has been suspended for the completion of the
(For example, 1 second) until the next switch operation
Invalid.

[0009]

1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a time chart thereof. In FIG. 1, when the dead battery detection circuit 2 detects a drop in the power supply voltage,
The detection voltage is sent to the interrupt input terminal of PU1. Thereby, the CPU 1 controls the infrared light emitting element 5 to transmit only one code.

As described above, since the internal resistance of the battery 6 increases when it is consumed, the terminal voltage decreases when a load current flows. The increase in the internal resistance becomes greater as the battery 6 is more consumed. For this reason, when the consumption of the battery 6 is small, even if the load current flows, the terminal voltage does not decrease much.
When the battery 6 is consumed a lot, the terminal voltage is greatly reduced.

On the other hand, when the battery is exhausted to the extent that the dead battery detection circuit 2 generates an output signal first, the terminal voltage of the battery 6 drops when a load current is supplied. It does not decrease to the minimum operating voltage of CPU1. In this example, the battery voltage is set to 3 V, the detection voltage V3 of the battery exhaustion detection circuit 2 is set to about 2.1 V , and when the battery is exhausted to the extent that the battery exhaustion is detected, the battery voltage takes about 100 ms to send one code. When the dead battery detection circuit 2 generates an output signal for the first time, the terminal voltage of the battery 6 does not decrease to the minimum operating voltage of the CPU 1 of 2.0V.

For this reason, even if the load current is supplied only for the time required to send one meaningful code of the remote controller, the battery exhaustion detecting circuit 2 detects the battery exhaustion before the power supply voltage reaches the minimum operating voltage of the CPU 1. Even if it is detected, the remote control operation can be performed for the time being. During this time, if the running out of battery is displayed on the liquid crystal display device 7, the remote control function does not stop immediately after the running out of battery is displayed, but the remote control can be used for a while.
Then, the user who has noticed this can replace the battery 6 and thereafter can use the remote control normally. The battery exhaustion notice is displayed for about 10 seconds, and is displayed every time the user performs a switch operation, and the state continues for several days to several weeks until the user becomes completely unusable. Therefore, even if the replacement is forgotten in the first display, the battery exhaustion display is performed each time, and the user notices that the battery needs to be replaced at an appropriate place, and the battery replacement is performed. As described above, the display of the battery exhaustion notice is turned off in about 10 seconds. However, depending on the application, the display period may be further extended, or may be kept lit. However, since it is not known whether or not the light is turned on due to a failure when the light is kept turned on, the light is turned off for a predetermined time when the user next operates, or the light is turned on again. It is easier to use if the user performs a process such as turning on after blinking for a predetermined time when the user next operates.

FIG. 2 (c)
When transmission stops even if a detection signal is output at time t1, the voltage eventually recovers to its original value, so the output signal from the dead battery detection circuit 2 stops within a predetermined time T as shown in FIG. I do. However, at the point in time t2 when the battery is consumed, the amount of voltage drop is further increased, and the time until the voltage is restored to the original value after the transmission is stopped is longer than in the case described above. The transmitted detection signal is longer than a predetermined time T as shown in (d).

Even after the output signal is generated by the battery exhaustion detection circuit 2, the code can be used if only about one code is used. However, if the battery is used as it is, the battery voltage eventually falls below the minimum operating voltage of the CPU 1 and malfunctions occur. cause. Therefore, in this example, the delay circuit 8 is provided, and when the duration of the output signal sent from the dead battery detection circuit 2 exceeds a predetermined value T, a reset signal is generated to reset the CPU 1 .

FIG. 2 is a time chart showing the above operation. When the switch 4 is operated as shown in FIG. 2A, a code signal is transmitted from the infrared light emitting element 5 a plurality of times during the operation. This is to ensure the operation by sending the code signal a plurality of times as described above. In this example, the code transmission period is selected to be about 100 ms. Since the load current flows from the battery 6 during the switch operation, the terminal voltage of the battery 6 gradually decreases as shown in (c), gradually increases when the switch 4 is opened, and eventually becomes almost the voltage before the switch operation. Restore to value.

When the battery 6 becomes exhausted, the voltage when the load current is supplied decreases, and at time t1, the dead battery detection circuit 2 generates an output signal and supplies it to the interrupt terminal of the CPU 1. As a result, CPU 1 does not send the code multiple times signal so far even if the switch 4 is operated, the code signal being transmitted
After the completion of one code transmission period of the signal, the emission of the infrared light emitting element 5 is stopped. For this reason, as shown in FIG.
The infrared light emitting element 5 is driven only for one code transmission period.

The output signal of the dead battery detection circuit 2 is also supplied to a delay circuit 8, where the consumption of the battery 6 is detected. This circuit includes, for example, as shown in FIG. 3, resistors 81 and 82, a capacitor 83, a switch 84, and a comparator 85. When a detection signal is supplied from the dead battery detection circuit 2, the switch 84 is opened. At the same time, the capacitor 83 is charged via the resistor 81. The terminal voltage of the capacitor 83 is supplied to the comparator 85 via the resistor 82. The comparator 85 generates a reset signal when the supplied voltage exceeds a predetermined value, and supplies the reset signal to the reset terminal of the CPU 1. I have.

As described above, by utilizing the fact that the length of the detection signal supplied from the battery exhaustion detection circuit 2 becomes longer as the battery 6 is consumed, the delay circuit 8 makes the signal length equal to or more than a predetermined value. To generate a reset signal when
Therefore , the CPU 1 can be reset before the power supply voltage reaches the minimum operating voltage of the CPU 1. That is,
It is possible to prevent a situation in which the CPU 1 is suddenly reset while the remote control is operating.

In this way, when the detection signal sent from the dead battery detection circuit 2 exceeds a predetermined time T as shown in FIG. 2D, a reset as shown in FIG. A signal is sent, which resets CPU1. The predetermined time T longer than the transmission period of the first code signal and sets the length supply voltage at the transmission completion time of one code signal is in a range capable of maintaining the minimum operating voltage (2.0 V) or more of the voltage of the CPU 1 I do. If the battery is repeatedly used when the battery voltage drops, the next operation is performed before the battery voltage is not restored. Therefore, the battery exhaustion detection circuit 2 operates to restore the battery voltage, and 1 After the code (100 ms) is emitted, the switch operation is invalidated for about one second and is not accepted. Since the battery voltage is restored during this one second, it is possible to prevent the next switch operation from being performed before the battery voltage is restored.

FIG. 4 is a block diagram showing another embodiment, in which diodes 10 and 12 and a capacitor 11 are provided so as to retain the memory contents even when the battery is removed. The diode 10 is for preventing backflow from the capacitor C1 when the battery is removed, and the diode 12 is for preventing the reset voltage from becoming higher than the power supply voltage.

[0021]

According to the present invention as it has been described above devised], electrostatic
It is detected that the battery voltage has dropped to the dead battery detection voltage.
Then, the code signal being transmitted is not interrupted immediately,
Will continue until the code transmission period is completed and then be interrupted.
The remote control should be used as soon as possible even if battery exhaustion is detected.
Can be used. In addition, the current supply period is short and transmission is performed.
Several days after battery exhaustion detected due to low voltage drop
To the extent that the power supply voltage drops to the minimum operating voltage of the CPU
In the meantime, it is possible to demonstrate the function of the remote control
It is said that you can replace the battery during this time
Has an effect. Also, the code signal being transmitted is one code transmission.
After being suspended for the completion of the communication period,
The next switch operation is invalid until 1 second elapses.
The next switch operation before the battery voltage is restored.
It can be prevented from being performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the apparatus shown in FIG.

FIG. 3 is a circuit diagram showing an example of a delay circuit used in the device of FIG.

FIG. 4 is a block diagram showing another embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional example.

FIG. 6 is a time chart showing the operation of the apparatus of FIG.

FIG. 7 is a diagram illustrating an example of a transmission code.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... CPU, 2 ... dead battery detection circuit, 4 ... switch, 5
... Light-emitting element, 6 ... Battery, 7 ... Liquid crystal display element, 8 ... Delay circuit, 10, 12 ... Diode, 11 ... Capacitor.

Continuation of the front page (56) References JP-A-4-81915 (JP, A) JP-A-4-178854 (JP, A) JP-A-5-189272 (JP, A) JP-A-4-355595 (JP) JP-A-2-250594 (JP, A) JP-A-3-48985 (JP, U)

Claims (2)

(57) [Scope of request for utility model registration] 1. A control of a CPU according to a switch operation.
The remote control unit repeatedly transmits multiple of the same code signal, detecting that monitors the battery voltage is the operating power supply, the battery voltage has dropped to the lowest operation voltage dead battery detection voltage set to be higher than the CPU When the
One code transmission period is completed without interrupting code signal immediately
Interrupting transmission interruption means were allowed to continue until a reset means for resetting the CPU when the time the battery exhaustion detection voltage is below the set value has continued more than a predetermined value, being sent by the transmission interruption means Code signal is 1
After a predetermined period of time elapses after the
Means for invalidating the next switch operation until the time passes. 2. The remote control unit according to claim 1, further comprising a voltage securing means for securing a memory holding voltage even during battery replacement.