Remote Controller

Abstract

A remote control (100) is provided with: a lithium ion battery (111); an infrared signal transmission unit (102) connected in parallel with the lithium ion battery (111) and a resistor (101), which is a first resistor connected in series with the infrared signal transmission unit (102); a microcomputer (105) that is connected in parallel with the lithium ion battery (111) and controls transmission of infrared signals from the infrared signal transmission unit (102); and a plurality of capacitors (106-110) including at least two ceramic capacitors connected in parallel with the microcomputer (105).

Description

[Technical field]

[0001] The present disclosure relates to a remote controller that uses a lithium-ion battery. [Background technology]

[0002] Conventionally, when operating an appliance such as an air conditioner, a user sets the desired temperature and the like using an attached remote controller (hereinafter referred to as a remote control). The remote control receives user operations through an input unit such as keys, and a control unit such as a microcomputer (hereinafter referred to as a microcomputer) controls the operation of the appliance such as an air conditioner by illuminating an infrared LED (Light Emitting Diode) in response to the user operation and transmitting an infrared signal to the appliance such as the air conditioner. Some remote controls include an internal electrolytic capacitor for stabilizing the power supply in order to stabilize the power supply voltage supplied to the microcomputer from an internal battery. For example, Patent Document 1 discloses a technology for suppressing heat generation due to short-circuit current even when an electrolytic capacitor for stabilizing the power supply is short-circuited in a remote control. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-316193 A Summary of the Invention [Problem to be solved by the invention]

[0004] Lithium-ion batteries are used in remote controls. The internal resistance of lithium-ion batteries increases due to deterioration over time caused by the air environment. In the circuit of a remote control that uses a lithium-ion battery, a current limiting resistor, transistors, etc. are connected in series to the infrared LED. A control unit such as a microcontroller adjusts the power supply to the infrared LED by controlling the on / off of the transistor, and controls the transmission of infrared signals. Usually, a bypass capacitor of about 0.1 μF recommended by the IC (Integrated Circuit) used as the microcontroller, and an electrolytic capacitor of about 10 μF to 47 μF for power supply stabilization as necessary, are mounted in parallel with the lithium-ion battery in the microcontroller. Usually, in a small remote control that uses a lithium-ion battery, unnecessary capacitors are not mounted due to reasons such as limited mounting space and cost considerations. Large-capacity capacitors are not mounted.

[0005] When a remote control with such a configuration is driven by a lithium-ion battery with a large internal resistance, current flowing through the infrared LED also flows through the internal resistance of the lithium-ion battery, causing the power supply voltage supplied from the lithium-ion battery, i.e. the power supply voltage inside the remote control, to drop. As a result, when the internal power supply voltage of the remote control falls below the reset voltage of the microcontroller, the microcontroller is reset, causing the problem that it is no longer possible to transmit infrared signals.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a remote controller that can prevent interruption of infrared signal transmission even when the internal resistance of a lithium-ion battery becomes large. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the remote controller according to the present disclosure includes a lithium ion battery, an infrared signal transmitting unit connected in parallel with the lithium ion battery and a first resistor connected in series to the infrared signal transmitting unit, a microcomputer connected in parallel with the lithium ion battery for controlling transmission of infrared signals from the infrared signal transmitting unit, and a plurality of capacitors including two or more ceramic capacitors connected in parallel with the microcomputer; a second resistor connected between the lithium ion battery, the microcomputer and the plurality of capacitors; Equipped with. The combined capacitance of the multiple capacitors is 200 μF or more, and the resistance value of the second resistor is 20 Ω or more. Effect of the Invention

[0008] The remote controller according to the present disclosure has an advantage in that it is possible to prevent interruption of transmission of infrared signals even when the internal resistance of the lithium ion battery becomes large. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a configuration example of a remote control according to a first embodiment; [Diagram 2] FIG. 13 is a diagram showing a configuration example of a remote control according to a second embodiment; [Diagram 3] FIG. 11 is a diagram showing an example of a data frame of an infrared signal transmitted from an infrared signal transmission unit of a remote control according to the second embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a remote controller according to an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0011] Embodiment 1 1 is a diagram showing an example of the configuration of a remote control 100 according to embodiment 1. The remote control 100 includes a resistor 101, an infrared signal transmitting unit 102, a transistor 103, a resistor 104, a microcomputer 105, capacitors 106 to 110, and a lithium ion battery 111. The remote control 100 is a remote controller used to operate a device such as an air conditioner (not shown).

[0012] The resistor 101 is a current limiting resistor connected in series to the infrared signal transmitting unit 102. In the following description, the resistor 101 may be referred to as a first resistor.

[0013] The infrared signal transmitting unit 102 transmits an infrared signal under the control of the microcomputer 105. The infrared signal transmitting unit 102 is, for example, an infrared LED, and transmits an infrared signal by emitting infrared rays when the infrared signal transmitting unit 102 is turned on by the transistor 103.

[0014] The transistor 103 is connected in series to the infrared signal transmitting unit 102, and is turned on and off under the control of the microcomputer 105 to adjust the conductivity of the infrared signal transmitting unit 102. The resistor 101, the infrared signal transmitting unit 102, and the transistor 103 are connected in parallel to the lithium ion battery 111.

[0015] Resistor 104 is a current limiting resistor connected in series to microcomputer 105. Resistor 104 is connected between lithium ion battery 111 and microcomputer 105 and capacitors 106 to 110. In the following description, resistor 104 may be referred to as a second resistor.

[0016] Microcomputer 105 is a microcomputer that controls the transmission of infrared signals from infrared signal transmission unit 102. Specifically, microcomputer 105 receives an operation from a user at an input unit (not shown) and controls the on / off of transistor 103 to transmit an infrared signal according to the content of the operation received from the user. Resistor 104 and microcomputer 105 are connected in parallel with lithium ion battery 111.

[0017] Capacitor 106 is connected between the power supply and ground (hereinafter referred to as GND) of microcomputer 105, and is a bypass capacitor with a capacitance of about 0.1 μF recommended by ICs and the like used in microcomputer 105. Capacitor 106 is, for example, a ceramic capacitor.

[0018] Capacitor 107 is connected between the power supply and GND of microcomputer 105, and is a power supply stabilizing electrolytic capacitor with a capacity of about 10 μF to 47 μF for stabilizing the power supply inside remote control 100.

[0019] Capacitors 108-110 are large-capacity ceramic capacitors connected between the power supply and GND of microcomputer 105 to maintain the power supply voltage inside remote control 100 until the transmission of the infrared signal from remote control 100 is completed. In the example of FIG. 1, remote control 100 includes capacitors 108-110, i.e., three ceramic capacitors, but this is not limited to this. The number of ceramic capacitors included in remote control 100 may be two or less, or four or more, depending on the required capacity as described later. Considering capacitor 106, remote control 100 includes at least two or more ceramic capacitors. In other words, remote control 100 includes a plurality of capacitors including two or more ceramic capacitors as capacitors 106-110 connected in parallel with microcomputer 105.

[0020] The lithium ion battery 111 is a battery that supplies a power supply voltage to the inside of the remote control 100. As described above, the lithium ion battery 111 has a characteristic that its internal resistance increases due to deterioration over time caused by the air environment.

[0021] The combined capacitance of the capacitors 106 to 110 is required to be 200 μF or more, although the calculation method will be described later. Generally, most remote controls 100 using the lithium ion battery 111 are small and do not have sufficient space for mounting components. For this reason, the remote control 100 uses ceramic capacitors, which have been available in a lineup of large capacitances in recent years, as the large-capacity capacitors 108 to 110 for maintaining the power supply voltage inside the remote control 100. Regarding the ceramic capacitors used as the capacitors 108 to 110, currently, ceramic capacitors with a capacity of 220 μF are the largest class in terms of cost and size balance. For this reason, the remote control 100 is configured to use about two to three ceramic capacitors with a capacity of 220 μF, depending on the required capacity, which is effective in solving the problem, that is, in maintaining the power supply voltage inside the remote control 100.

[0022] In addition, in the remote control 100, current is supplied to the infrared signal transmitting unit 102 from the capacitors 108-110, which are large-capacity ceramic capacitors, but there is a concern that too much current may flow from the capacitors 108-110 to the infrared signal transmitting unit 102. If too much current flows to the infrared signal transmitting unit 102, the infrared signal transmitting unit 102 cannot transmit an infrared signal for a long period of time. For this reason, in this embodiment, the remote control 100 includes a resistor 104 for current limiting resistance in series with the power supply side of the microcomputer 105, so that the infrared signal transmitting unit 102 can maintain a charge while transmitting an infrared signal.

[0023] The remote control 100 uses ceramic capacitors 108-110 with an adjusted balance between their capacitances and the resistance of the resistor 104, so that the power supply voltage can be maintained when the infrared signal transmitting unit 102 transmits an infrared signal. The resistor 104 is arranged in series between the lithium ion battery 111 and the microcomputer 105, and therefore a resistor with a very large resistance is not usually selected because there is a risk of the voltage supplied to the microcomputer 105 decreasing when a current flows through the microcomputer 105. The resistance value of the resistor 104 is empirically selected to be about 10Ω, but in this embodiment, it is desirable to select a resistance value of 20Ω or more in order to prevent the capacitance of the capacitors 106-110 from becoming too large, although this depends on the balance with the combined capacitance of the capacitors 106-110.

[0024] The constants of each element of the circuit constituting the remote control 100 will be described in detail. In the remote control 100, the voltage supplied to the microcomputer 105 when a current flows through the infrared signal transmission unit 102 is determined by the resistance value of the resistor 101, the resistance value of the resistor 104, the combined capacitance of the capacitors 106 to 110, and the resistance value of the internal resistance of the lithium ion battery 111. The resistor 101 is selected to have a resistance value such that, when a lithium ion battery 111 with a low internal resistance, that is, a normal battery not degraded, is used, the transmission distance of the infrared signal from the infrared signal transmission unit 102 satisfies the required specifications and also satisfies the maximum rating of the lithium ion battery 111. The remote control 100 uses the constants of the capacitors 106 to 110, the resistor 101, and the resistor 104 that satisfy the requirements of the following formula (1).

[0025] C>-t / (R×ln(V1 / V0)) …(1)

[0026] In formula (1), C is the combined capacitance of capacitors 106 to 110. R is the combined resistance of resistors 101 and 104. V0 is the reset voltage of microcomputer 105. V1 is the power supply voltage supplied from lithium ion battery 111. t is the total time during which an infrared signal is actually transmitted from remote control 100, i.e., infrared signal transmission unit 102. t can also be said to be the total time during which infrared signal transmission unit 102 is conductive due to transistor 103.

[0027] For example, if the resistance value of the internal resistance of the lithium ion battery 111 increases to about 300Ω, the current supply from the lithium ion battery 111 becomes 1 / 10 or less compared to when the resistance value of the internal resistance of the lithium ion battery 111 is small, and can be approximated by the formula (1). When the formula (1) is calculated, a realistic combined capacitance of the capacitors 106 to 110 is 200 μF or more, the resistance value of the resistor 101 is about 10 to 20Ω, and the resistance value of the resistor 104 is 20Ω or more. By using the capacitors 106 to 110, the resistor 101, and the resistor 104 with the above constants, the remote control 100 can continue to transmit an infrared signal from the infrared signal transmitting unit 102 even if the internal resistance of the lithium ion battery 111 increases. In addition, the above constants have been experimentally proven to be effective, and the remote control 100 can prevent the power supply voltage inside the remote control 100 from reaching the reset voltage of the microcomputer 105 until the transmission of the infrared signal from the infrared signal transmitting unit 102 is completed.

[0028] As described above, according to this embodiment, remote control 100 is provided between the power supply of microcomputer 105 and GND with capacitors 108-110, which are large-capacity ceramic capacitors that generally cannot be provided in small remote controls due to space limitations. Remote control 100 also uses capacitors 106-110, resistor 101, and resistor 104 whose constants are adjusted so that the power supply voltage inside remote control 100 does not become equal to or lower than the reset voltage of microcomputer 105 even if the resistance value of the internal resistance of lithium ion battery 111 increases. As a result, remote control 100 can prevent interruption of transmission of infrared signals without resetting microcomputer 105 even if the resistance value of the internal resistance of lithium ion battery 111 increases, and can continue transmitting infrared signals.

[0029] Embodiment 2 In the second embodiment, a case will be described in which the microcomputer includes a voltage monitoring port.

[0030] Fig. 2 is a diagram showing an example of the configuration of a remote control 100a according to the second embodiment. The remote control 100a is obtained by replacing the microcomputer 105 with a microcomputer 105a in the remote control 100 shown in Fig. 1. The microcomputer 105a includes a voltage monitoring port 112. The voltage monitoring port 112 uses an AD (Analog to Digital) conversion function of the microcomputer 105a, and monitors the power supply voltage supplied from a lithium ion battery 111 as shown in Fig. 2.

[0031] In remote control 100a, if the internal resistance of lithium ion battery 111 is large, the voltage drop across both ends of lithium ion battery 111 will be rapid when a current flows through infrared signal transmission unit 102. This is calculated by the following formula (2).

[0032] V = Vb - Iled1 × Rb … (2)

[0033] In equation (2), V is the voltage monitored, i.e., detected, by the voltage monitoring port 112. Vb is the power supply voltage supplied from the lithium ion battery 111. Iled1 is the current flowing through the infrared signal transmitting unit 102. Rb is the resistance value of the internal resistance of the lithium ion battery 111.

[0034] By using formula (2), the microcomputer 105a checks the difference between the voltage monitored at the voltage monitoring port 112 when a current is flowing through the infrared signal transmission unit 102 and the voltage monitored at the voltage monitoring port 112 when no current is flowing through the infrared signal transmission unit 102, and if the difference is equal to or greater than a specified threshold, it can detect that the resistance value of the internal resistance of the lithium ion battery 111 has increased. Therefore, the microcomputer 105a monitors the voltage monitoring port 112 when transmitting an infrared signal from the infrared signal transmission unit 102, and adjusts the length of the infrared signal transmitted from the infrared signal transmission unit 102 if it detects that the resistance value of the internal resistance of the lithium ion battery 111 has increased.

[0035] That is, the microcomputer 105a detects the resistance value of the internal resistance of the lithium ion battery 111 based on the fluctuation of the power supply voltage supplied from the lithium ion battery 111 detected at the voltage monitoring port 112, and adjusts the transmission pattern of the infrared signal transmitted from the infrared signal transmitting unit 102 according to the detected resistance value. Note that the microcomputer 105a may cause the infrared signal transmitting unit 102 to transmit an infrared signal on a test basis to detect the resistance value of the internal resistance of the lithium ion battery 111 not only when the infrared signal is transmitted from the infrared signal transmitting unit 102 based on a user's operation, but also before the infrared signal is transmitted from the infrared signal transmitting unit 102 based on a user's operation.

[0036] 3 is a diagram showing an example of a data frame of an infrared signal transmitted from the infrared signal transmitting unit 102 of the remote control 100a according to the second embodiment. The diagram shown in the upper part of FIG. 3 is a data frame of an infrared signal transmitted from the infrared signal transmitting unit 102, and shows a dummy frame 401, a transmission prohibited section 402, and a main frame 403. The diagram shown in the lower part of FIG. 3 shows actual data bits 404 in the main frame 403, and a bit length 405 of one bit. The remote control 100a may transmit a dummy frame 401 once at a specified time when transmitting an infrared signal from the infrared signal transmitting unit 102 as shown in FIG. 3, and after stabilizing the receiving performance of the light receiving element of the device receiving the infrared signal, transmit a main frame 403 including actual transmission data after the transmission prohibited section 402.

[0037] The remote control 100a transmits the dummy frame 401 to stabilize the receiving performance of the light receiving element of the device that receives the infrared signal, thereby increasing the transmission distance of the infrared signal, specifically the main frame 403. On the other hand, when the resistance value of the internal resistance of the lithium ion battery 111 increases and the power supply voltage supplied to the microcomputer 105a becomes equal to or lower than the reset voltage of the microcomputer 105a, the remote control 100a stops transmitting the infrared signal midway. In such a case, the remote control 100a needs to prioritize being able to transmit the infrared signal to the end over increasing the transmission distance of the infrared signal. Therefore, the remote control 100a does not transmit the dummy frame 401. As a result, the remote control 100a can shorten the conduction time of the infrared signal transmitting unit 102 and increase the power supply time from the lithium ion battery 111 to the capacitors 106 to 110, thereby preventing the power supply voltage supplied to the microcomputer 105a from becoming equal to or lower than the reset voltage. At this time, the microcomputer 105a determines whether or not to transmit the dummy frame 401 in the transmission pattern of the infrared signal transmitted from the infrared signal transmitting unit 102, depending on the detected resistance value of the internal resistance of the lithium ion battery 111.

[0038] As shown in FIG. 3, the main frame 403 includes data bits 404, and the bit length 405 of one bit of the data bits 404 has a prescribed range. The remote control 100a usually transmits an infrared signal with the bit length 405 set to the median value of the prescribed range in order to stabilize the receiving performance of the light receiving element of the device that receives the infrared signal. In this embodiment, the remote control 100a changes the bit length 405 of the on time to a value close to the lower limit of the prescribed range and transmits an infrared signal, and further changes the bit length 405 of the off time to a value close to the upper limit of the prescribed range, thereby shortening the on time overall when transmitting the main frame 403 and lengthening the off time overall. The on time is the time when the data bits 404 are high in FIG. 3 and the infrared signal transmitting unit 102 actually emits infrared rays. The off time is the time when the data bits 404 are low in FIG. 3 and the infrared signal transmitting unit 102 does not emit infrared rays. This allows the remote control 100a to shorten the conduction time of the infrared signal transmitting unit 102 and increase the time for which power is supplied from the lithium ion battery 111 to the capacitors 106 to 110, thereby preventing the power supply voltage supplied to the microcomputer 105a from falling below the reset voltage.

[0039] In this way, the remote control 100a performs processes such as the microcomputer 105a monitoring the voltage using the voltage monitoring port 112, not transmitting the dummy frame 401, and changing the bit length 405 of the data bits 404 between the on time and the off time, thereby making it possible to reduce the capacitance of the capacitors 106-110, and thus suppressing resetting of the microcomputer 105a and reducing the cost of the capacitors 106-110. At this time, the microcomputer 105a shortens the bit length 405 of the data bits 404 in the on time of the transmission data, or lengthens the bit length 405 of the data bits 404 in the off time of the transmission data, or shortens the bit length 405 of the data bits 404 in the on time of the transmission data and lengthens the bit length 405 of the data bits 404 in the off time of the transmission data, in the transmission pattern of the infrared signal transmitted from the infrared signal transmitting unit 102, according to the detected resistance value of the internal resistance of the lithium ion battery 111.

[0040] As described above, according to this embodiment, in the remote control 100a, the microcomputer 105a includes the voltage monitoring port 112, detects the resistance value of the internal resistance of the lithium ion battery 111 based on the fluctuation of the power supply voltage supplied from the lithium ion battery 111 detected by the voltage monitoring port 112, and adjusts the transmission pattern of the infrared signal transmitted from the infrared signal transmitting unit 102 according to the detected resistance value. This allows the remote control 100a to reduce the time during which the infrared signal transmitting unit 102 actually emits light and transmits an infrared signal, thereby reducing the current consumption of the remote control 100a. As a result, the remote control 100a can be driven with a lower power supply voltage and can transmit an infrared signal even when the lithium ion battery 111 has a small remaining battery charge, which also has the effect of extending the battery life.

[0041] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0042] 100,100a remote control, 101,104 resistor, 102 infrared signal transmitter, 103 transistor, 105,105a microcomputer, 106 capacitor (bypass capacitor), 107 capacitor (electrolytic capacitor for stabilizing power supply), 108 to 110 capacitor (ceramic capacitor), 111 lithium ion battery, 112 voltage monitoring port, 401 dummy frame, 402 transmission prohibited section, 403 main frame, 404 data bit, 405 bit length.

Claims

1. A lithium-ion battery; an infrared signal transmitting unit connected in parallel with the lithium ion battery and a first resistor connected in series with the infrared signal transmitting unit; a microcomputer that controls the transmission of infrared signals from the infrared signal transmitting unit, the microcomputer being connected in parallel with the lithium ion battery; a plurality of capacitors, including two or more ceramic capacitors, connected in parallel with the microcomputer; a second resistor connected between the lithium ion battery, the microcomputer and the plurality of capacitors; Equipped with a combined capacitance of the plurality of capacitors is 200 μF or more, and a resistance value of the second resistor is 20 Ω or more; Remote controller.

2. A lithium ion battery; an infrared signal transmitting unit connected in parallel with the lithium ion battery and a first resistor connected in series with the infrared signal transmitting unit; a microcomputer that controls the transmission of infrared signals from the infrared signal transmitting unit, the microcomputer being connected in parallel with the lithium ion battery; a plurality of capacitors, including two or more ceramic capacitors, connected in parallel with the microcomputer; a second resistor connected between the lithium ion battery, the microcomputer and the plurality of capacitors; Equipped with The combined capacitance of the plurality of capacitors is C, A combined resistance of the first resistor and the second resistor is R, The reset voltage of the microcomputer is V0, The power supply voltage supplied from the lithium ion battery is V1, The total time during which the infrared signal is transmitted from the infrared signal transmission unit is denoted by t, Using the plurality of capacitors, the first resistor, and the second resistor, whose constants satisfy the requirement of the formula C>-t / (R×ln(V1 / V0)); Remote controller.

3. A lithium ion battery; an infrared signal transmitting unit connected in parallel with the lithium ion battery and a first resistor connected in series with the infrared signal transmitting unit; a microcomputer that controls the transmission of infrared signals from the infrared signal transmitting unit, the microcomputer being connected in parallel with the lithium ion battery; a plurality of capacitors, including two or more ceramic capacitors, connected in parallel with the microcomputer; Equipped with the microcomputer includes a voltage detection port, detects a resistance value of an internal resistance of the lithium ion battery based on a fluctuation in a power supply voltage supplied from the lithium ion battery detected at the voltage detection port, and adjusts a transmission pattern of the infrared signal transmitted from the infrared signal transmitter in accordance with the detected resistance value. Remote controller.

4. the microcomputer detects a resistance value of an internal resistance of the lithium ion battery when the infrared signal is transmitted from the infrared signal transmission unit based on a user's operation or before the infrared signal is transmitted from the infrared signal transmission unit based on a user's operation, and determines whether or not to transmit a dummy frame in a transmission pattern of the infrared signal transmitted from the infrared signal transmission unit according to the detected resistance value. The remote controller according to claim 3 .

5. the microcomputer detects a resistance value of an internal resistance of the lithium ion battery when the infrared signal is transmitted from the infrared signal transmitting unit based on a user's operation or before the infrared signal is transmitted from the infrared signal transmitting unit based on a user's operation, and, in a transmission pattern of the infrared signal transmitted from the infrared signal transmitting unit, shortens the bit length of a data bit during an ON time of transmission data, or lengthens the bit length of a data bit during an OFF time of transmission data, or shortens the bit length of the data bit during the ON time of transmission data and lengthens the bit length of the data bit during the OFF time of transmission data, depending on the detected resistance value; The remote controller according to claim 3 .

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