JP2005285517A - Fluorescent tube system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To respond to a request for designing with due consideration on load maximizing conditions and fusion characteristics of a fuse, in constituting a power source of the fuse. <P>SOLUTION: The fluorescent tube system provided with a fluorescent tube part, a power source supplying power to the fluorescent tube part, a fluorescent tube part control part, and a power source control part, is further provided with a fluorescent tube part voltage information obtaining part for obtaining fluorescent tube part voltage information as information showing a voltage of the fluorescent tube part, a first normal voltage information retaining part for retaining first normal voltage information as the information of a voltage which the fluorescent tube part has in a normal state in accordance with the control state of the fluorescent tube control part, a first comparison part for comparing the fluorescent tube part voltage information obtained by the fluorescent tube part voltage information obtaining part with the first normal voltage information retained by the first normal voltage information retaining part, and a first self-driving part for driving the fluorescent tube part control part or/and the power source part control part based on the comparison result at the first comparison part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluorescent tube system used for a liquid crystal display having a backlight.

  Conventionally, protection circuits such as a liquid crystal display having a backlight, such as a liquid crystal monitor, a liquid crystal television, a notebook computer, and an in-vehicle car navigation system, have a large load fluctuation due to dimming, and have a configuration in which a power supply unit that supplies power has a fuse It is common. The backlight is also provided with a protection circuit that shuts off the power supply when the fluorescent tube current decreases due to damage to the fluorescent tube that is a constituent element of the backlight. Regarding a light source driving circuit having a protection circuit, Patent Literature 1 and Patent Literature 2 are disclosed.

  In Patent Document 1, an inverter that converts a DC power source into DC-AC and outputs it to a backlight includes a DC-AC conversion circuit, an output current detection circuit, a tube current detection circuit, an overcurrent setting circuit, and a tube current. And a setting circuit. The DC-AC conversion circuit converts a DC power source into DC-AC. The output current detection circuit detects an output current from the DC-AC conversion circuit to the backlight. The tube current detection circuit detects the tube current of the backlight. The overcurrent setting circuit determines that the detection value of the output current detection circuit is an overcurrent, and stops the operation of the DC-AC conversion circuit. The tube current setting circuit sets a tube current value according to a command from the outside, controls the DC-AC conversion circuit, and adjusts a set value level of the overcurrent setting circuit. As described above, Patent Document 1 discloses a technique for providing an inverter with a protection circuit that can function well even in the entire dimming range.

Further, in Patent Document 2, when the discharge lamp lighting device is provided with means for detecting a high-frequency voltage applied to the discharge lamp, and the high-frequency voltage is discharged between the low-voltage part, the high-frequency voltage is normally discharged. A protection circuit is disclosed in which an abnormality in the high-frequency voltage is determined because the voltage value is lower than the voltage value when the lamp is lit, and the operation of the discharge lamp lighting device is stopped.
JP 11-355960 A JP 11-121190 A

  However, when the power supply unit is composed of a fuse as in the above-described fluorescent tube system, a design that fully considers the maximum load condition and the fusing characteristics of the fuse is required. When a fuse is actually used, a certain amount of current margin is required so as not to be blown even by an instantaneous overcurrent such as an instantaneous short circuit due to unexpected foreign matter mixing or a rush current at power-on. This is because, if it is easily cut, it is necessary to replace the parts frequently, and measures are taken so as not to blow unless sufficient current flows. However, this measure has a problem that there is a risk of damaging the control circuit component in the front stage of the fluorescent tube. In addition, conventional protection circuits are configured to detect inverters and fluorescent tube abnormalities and control them independently. In the future, liquid crystal televisions will also pursue higher added value in terms of specifications by shifting to larger sizes. There is a growing demand for protection circuits that allow complex control.

  The present invention has been made in view of the above problems.

  A first invention is a fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit, A fluorescent tube unit voltage information acquisition unit that acquires fluorescent tube unit voltage information that is information indicating a voltage, and information on a voltage that the fluorescent tube unit should have in a normal state according to a control state of the fluorescent tube unit control unit. A first normal voltage information holding unit that holds certain first normal voltage information, a fluorescent tube unit voltage information acquired by the fluorescent tube unit voltage information acquisition unit, and a first normal that the first normal voltage information holding unit holds A first comparison unit that compares voltage information; and a first self-drive unit that drives the fluorescent tube unit control unit and / or the power supply unit control unit based on a comparison result in the first comparison unit. The present invention relates to a fluorescent tube system.

  The second invention relates to the fluorescent tube system according to the first invention, wherein the first normal voltage information holding unit holds a plurality of pieces of first normal voltage information according to the control state.

  According to a third aspect of the invention, the first comparison unit includes a selection comparison unit that obtains specific first normal voltage information from a plurality of first normal voltage information according to the control state and performs comparison. To the fluorescent tube system described in 1.

  A fourth invention is a fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit, wherein the voltage of the power supply unit A power supply unit voltage information acquisition unit that acquires power supply unit voltage information that is information indicating the second normal voltage that is information on a voltage that the power supply unit should have in a normal state according to a control state of the power supply unit control unit A second normal voltage information holding unit for holding information, a power supply unit voltage information acquired by the power supply unit voltage information acquisition unit, and a second normal voltage information held by the second normal voltage information holding unit. The present invention relates to a fluorescent tube system having two comparison units and a second self-driving unit that drives the fluorescent tube unit control unit and / or the power supply unit control unit based on a comparison result in the second comparison unit.

  A fifth invention relates to the fluorescent tube system according to the fourth invention, wherein the second normal voltage information holding unit holds a plurality of second normal voltage information corresponding to the control state.

  In a sixth aspect of the present invention, the second comparison unit includes a selection comparison unit that obtains and compares specific second normal voltage information from a plurality of second normal voltage information according to the control state. To the fluorescent tube system described in 1.

  A seventh invention is a fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit, A fluorescent tube unit voltage information acquisition unit that acquires fluorescent tube unit voltage information that is information indicating a voltage, and information on a voltage that the fluorescent tube unit should have in a normal state according to a control state of the fluorescent tube unit control unit. A first normal voltage information holding unit that holds certain first normal voltage information, a fluorescent tube unit voltage information acquired by the fluorescent tube unit voltage information acquisition unit, and a first normal that the first normal voltage information holding unit holds A first comparison unit that compares voltage information, a transient state voltage information acquisition unit that acquires transient state voltage information that is information indicating a voltage in a transient state of the fluorescent tube unit, and the fluorescent tube unit is in a normal state. Holds third normal voltage information, which is information indicating the transient voltage to be Three normal voltage information holding unit, a third comparison unit that compares the transient state voltage information acquired by the transient state voltage information acquisition unit, and the third normal voltage information held by the third normal voltage information holding unit, A fluorescent tube comprising: a third self-driving unit that drives the fluorescent tube unit control unit and / or the power supply unit control unit based on a comparison result in the third comparison unit and a comparison result in the first comparison unit About the system.

  An eighth invention is a fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit, wherein the voltage of the power supply unit A power supply unit voltage information acquisition unit that acquires power supply unit voltage information that is information indicating the second normal voltage that is information on a voltage that the power supply unit should have in a normal state according to a control state of the power supply unit control unit A second normal voltage information holding unit for holding information, a power supply unit voltage information acquired by the power supply unit voltage information acquisition unit, and a second normal voltage information held by the second normal voltage information holding unit. Two comparison units, a transient state voltage information acquisition unit that acquires transient state voltage information that is information indicating a voltage in a transient state of the fluorescent tube unit, and a transient state voltage that the fluorescent tube unit should have in a normal state Third normal voltage information that holds third normal voltage information A third comparison unit that compares the holding unit, the transient state voltage information acquired by the transient state voltage information acquisition unit, and the third normal voltage information held by the third normal voltage information holding unit; and the third comparison And a fourth self-driving unit that drives the fluorescent tube unit control unit and / or the power supply unit control unit based on a comparison result in the unit and a comparison result in the second comparison unit.

  A ninth invention is a fluorescent tube system having a fluorescent tube unit, a power supply unit for supplying power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit, A fluorescent tube unit voltage information acquisition unit that acquires fluorescent tube unit voltage information that is information indicating a voltage, and information on a voltage that the fluorescent tube unit should have in a normal state according to a control state of the fluorescent tube unit control unit. A first normal voltage information holding unit that holds certain first normal voltage information, a fluorescent tube unit voltage information acquired by the fluorescent tube unit voltage information acquisition unit, and a first normal that the first normal voltage information holding unit holds A first comparison unit that compares voltage information; a power supply unit voltage information acquisition unit that acquires power supply unit voltage information that is information indicating a voltage of the power supply unit; and the power supply according to a control state of the power supply unit control unit Holds second normal voltage information, which is information on the voltage that the unit should have in a normal state A second normal voltage information holding unit; a power supply unit voltage information acquired by the power supply unit voltage information acquisition unit; and a second comparison unit that compares the second normal voltage information held by the second normal voltage information holding unit; A transient state voltage information acquisition unit that acquires transient state voltage information that is information indicating a transient state voltage of the fluorescent tube unit, and information indicating a transient state voltage that the fluorescent tube unit should have in a normal state A third normal voltage information holding unit for holding third normal voltage information; a transient state voltage information acquired by the transient state voltage information acquisition unit; a third normal voltage information held by the third normal voltage information holding unit; Based on the comparison result in the third comparison part, the comparison result in the third comparison part, the comparison result in the second comparison part, and the comparison result in the first comparison part, or And a fifth self-driving unit that drives the power source control unit Relates to a fluorescent tube system with.

  According to the fluorescent tube system of the present invention, it is possible to provide a smooth protection condition by measuring the transient state of the power supply voltage and the timing of dimming. The present invention also relates to external control (for example, user control: key operation) such as a potential that can be controlled by detecting a transient state of the power supply voltage and dimming (brightness control: large load fluctuation). Has characteristics.

  Embodiments of the present invention will be described below. The relationship between the embodiment and the claims is generally as follows. Note that the present invention is not limited to these embodiments, and can be implemented in various modes without departing from the spirit of the present invention. The first embodiment mainly describes claims 1, 2, 3 and the like. The second embodiment mainly describes claims 4, 5, 6 and the like. The third embodiment mainly describes claim 7. The fourth embodiment will mainly describe claim 8. The fifth embodiment will mainly describe claim 9.

<< Embodiment 1 >>
Embodiment 1 of the fluorescent tube system of the present invention will be described below.

<Concept of Embodiment 1>
The concept of this embodiment will be described below. The fluorescent tube system according to the present embodiment monitors the tube voltage of the fluorescent tube unit to drive the fluorescent tube unit control unit and / or the power supply unit control unit in accordance with the detected tube voltage, so that the fluorescent tube unit or / And protecting the power supply unit.

<Clarification of configuration requirements>
In the following, the configuration requirements of this embodiment will be clarified.
FIG. 1 is a functional block diagram of the fluorescent tube system of the present embodiment. The fluorescent tube system 0100 of the present embodiment includes a fluorescent tube unit 0101, a power supply unit 0102, a fluorescent tube unit control unit 0103, a power supply unit control unit 0104, a fluorescent tube unit voltage information acquisition unit 0105, and a first normal voltage. An information holding unit 0106, a first comparison unit 0107, and a first self-driving unit 0108 are included.

<Description of configuration requirements>
The configuration requirements of this embodiment will be described below.

(Fluorescent tube part)
The “fluorescent tube portion” refers to a light source used for a backlight such as a liquid crystal display. The fluorescent tube section corresponds to a cold cathode tube (CCFT) or a hot cathode tube (HCFT) which is a kind of fluorescent lamp. The fluorescent lamp is a type in which the discharge electrode portion is not a filament, and mercury ultraviolet light generated by discharge excites the phosphor to emit visible light. In addition, the cold cathode tube is characterized in that the luminance is slightly lower but the tube diameter can be made thinner and the life is longer because the current cannot flow compared to the hot cathode tube. Here, the “backlight” is a portion that supplies a light source installed on the back surface of a liquid crystal display or the like. The backlight is composed of a fluorescent lamp (hot cathode tube or cold cathode tube), a light guide plate, a diffusion plate (sheet), or the like, which is a fluorescent tube portion.

  The cold cathode tube used as the fluorescent tube section changes in luminance and electrical characteristics depending on the tube-specific properties such as the tube length, tube diameter, gas type and gas pressure, and ambient temperature. Although depending on the type of tube, as an example, discharge is started by applying a high voltage of about 500 to 1600 Vrms (Voltage Root Mean Square) to the electrodes at both ends of the cold cathode tube. This voltage is called a discharge start voltage. Here, the “effective value of voltage” mathematically means a value obtained by squaring a voltage waveform, taking an average value, and taking the square root thereof. When an AC voltage of X (Vrms) is applied to the pure resistance and when a DC voltage of X (V) is applied, the energy consumed by the pure resistance is the same. Moreover, the frequency of the alternating tube voltage concerning a fluorescent tube part is 50 KHz-60 KHz as an example.

  When a current flows through the cold cathode tube, the impedance of the tube is lowered and the voltage between both electrodes of the cold cathode tube is rapidly reduced. However, when the current flows to a certain extent, the decrease in voltage becomes gradual and almost constant voltage characteristics are exhibited. The voltage at this time is called tube voltage. As an example, the tube voltage corresponds to a voltage of about 300 to 1300 Vrms.

  FIG. 2 is a diagram showing an example of voltage (V) -current (I) characteristics of the fluorescent tube section. When a current starts to flow through the fluorescent tube portion, the voltage of the fluorescent tube portion suddenly increases at first, but when a certain amount of current flows, the voltage of the fluorescent tube portion decreases rapidly. However, it can be seen that when the current flows to a certain extent, the decrease in voltage becomes gradual and almost constant voltage characteristics are exhibited.

(Power supply part)
The “power supply unit” refers to a part that supplies power to the fluorescent tube system. The voltage supplied by the power supply unit corresponds to a power supply of 100 V that is the voltage of the commercial power supply. Further, the voltage of the power supply unit may be a DC voltage of about 6 to 15 V obtained by AC-DC conversion from a 100 V power source. The power supplied from the power supply unit is DC-AC converted and voltage converted by an inverter, a transformer, etc., and supplied to the fluorescent tube unit. Note that the functional block diagram of the fluorescent tube system in FIG. 1 does not show an inverter, a transformer, or the like. Further, the inverter and the transformer may be present inside the power supply unit.

(Fluorescent tube control unit)
The “fluorescent tube unit control unit” refers to a part that controls the luminance and the like of the fluorescent tube unit by adjusting the voltage and current of the fluorescent tube unit. The fluorescent tube unit control unit controls the fluorescent tube unit by a signal from the first self-driving unit. As an example, the control of the fluorescent tube unit includes control for lowering the brightness of the fluorescent tube unit, control for increasing the luminance, control for maintaining, control for blocking, and the like.

(Power supply control unit)
The “power supply control unit” refers to a part that controls the voltage, current, and the like of the power supply unit. The power supply unit control unit controls the power supply unit by a signal from the first self-driving unit. As an example, the control of the power supply unit includes control for lowering the voltage of the power supply unit, control for increasing the voltage, control for maintaining, control for cutting off, and the like.

(Fluorescent tube voltage information acquisition unit)
The “fluorescent tube section voltage information acquisition unit” acquires fluorescent tube section voltage information. Here, “fluorescent tube section voltage information” refers to information indicating the voltage of the fluorescent tube section. For example, a voltage of about 300 to 1300 Vrms corresponds to the fluorescent tube voltage information.

(First normal voltage information holding unit)
The “first normal voltage information holding unit” holds first normal voltage information. Here, the “first normal voltage information” refers to information on the voltage that the fluorescent tube unit should have in a normal state according to the control state of the fluorescent tube unit control unit. Further, “according to the control state of the fluorescent tube control unit” means according to a voltage value controlled by the fluorescent tube control unit in accordance with a voltage value set by external user control. The “normal state” refers to a voltage value in a state within the set voltage range. As an example, the first normal voltage information corresponds to a voltage value within a range of 475 to 525 Vrms. In addition to the voltage value, the first normal voltage information may include information corresponding to the luminance of the fluorescent tube, for example, additional information such as “bright”, “normal”, and “dark”. Furthermore, the first normal voltage information is not limited to a voltage value having a certain width regardless of time, but may be a voltage value related to time. The voltage value related to the time is not limited to the voltage value at a specific time, and may be a voltage value having a certain time width. For example, a voltage value having a width in one second may be used.

  The first normal voltage information holding unit can also hold a plurality of pieces of first normal voltage information corresponding to the control state. As an example, the first normal voltage information holding unit includes a plurality of first normal voltage information corresponding to the luminance of the fluorescent tube unit, for example, a plurality of voltages corresponding to luminances such as “bright”, “normal”, and “dark”. Can hold a value. In this case, it becomes possible to control the fluorescent tube section so as to have a suitable luminance in accordance with the use situation of a liquid crystal display or the like.

(First comparison part)
The “first comparison unit” compares the fluorescent tube unit voltage information acquired by the fluorescent tube unit voltage information acquisition unit with the first normal voltage information stored in the first normal voltage information storage unit. As an example, when the voltage value indicated by the fluorescent tube voltage information is higher than the voltage value in the range indicated by the first normal voltage information as a result of the comparison, the first comparison unit outputs a signal “H”. Is output to the first self-driving unit. As a result of the comparison, when the voltage value indicated by the fluorescent tube voltage information is lower than the voltage value in the range indicated by the first normal voltage information, the first comparison unit outputs the “L” signal Output to one self-driving unit. Further, as a result of the comparison, when the voltage value indicated by the fluorescent tube part voltage information is within the voltage value range indicated by the first normal voltage information, the first comparison part sends a signal to the first self-driving part. Output (for example, high impedance state). The output of the first comparison unit may be digital data output.

  Further, when the first normal voltage information holding unit holds a plurality of first normal voltage information according to the control state, the first comparison unit determines a specific first information from the plurality of first normal voltage information according to the control state. It can also be configured to have a selective comparison means for acquiring and comparing one normal voltage information. As an example, the first normal voltage information holding unit has a plurality of voltage values corresponding to luminances such as “bright”, “normal”, “dark” as a plurality of first normal voltage information corresponding to the luminance of the fluorescent tube unit. Is stored, the selection / comparison unit can acquire and compare the first normal voltage information corresponding to “bright”. The specific first normal voltage information may be acquired manually from the outside of the fluorescent tube system by key input or may be acquired from a memory such as a ROM set in advance inside the fluorescent tube system. When the selective comparison means obtains specific information from a plurality of first normal voltage information set in advance in the fluorescent tube system, it is specified so that the luminance of the fluorescent tube can be automatically changed according to the time zone. It is also possible to acquire the first normal voltage information. For example, “bright” can be selected during the time when the sunlight is relatively strong from morning to evening, and “normal” and “dark” can be selected during the night when there is no sunlight. it can.

(First self-driving unit)
The “first self-driving unit” drives the fluorescent tube unit control unit and / or the power source unit control unit based on the comparison result in the first comparison unit. Here, “based on the comparison result” means that the fluorescent tube controller or / and the power supply controller are driven according to the signal output from the first comparator. Here, “drive” means to drive the fluorescent tube control unit or / and the power supply control unit so that the fluorescent tube unit or / and the power supply unit have a predetermined voltage. “Predetermined voltage” refers to a voltage set when designing a fluorescent tube system. As an example, when the output from the first comparison unit is “H”, the first self-driving unit drives the fluorescent tube control unit so that the fluorescent tube unit has low luminance. Or you may drive a fluorescent tube control part so that the voltage of a fluorescent tube part may be interrupted | blocked. As an example, when the output from the first comparison unit is “H”, the first self-driving unit drives the power supply unit control unit so that the power supply unit has a low voltage. Or you may drive a power supply control part so that the voltage of a power supply part may be interrupted | blocked.

  FIG. 3 is a table showing an example of control of the first self-driving unit. For example, it is assumed that the first normal voltage information holding unit holds a voltage value of 475 to 525 Vrms. At this time, it is assumed that the fluorescent tube voltage information acquired by the fluorescent tube voltage information acquiring unit is 550 Vrms. The first comparison unit compares the fluorescent tube unit voltage information 550 Vrms acquired by the fluorescent tube unit voltage information acquisition unit with the first normal voltage information 475 to 525 Vrms held by the first normal voltage information holding unit, and the fluorescent tube unit voltage Since the information has a higher voltage value, an “H” signal is output to the first self-driving unit. The first self-driving unit that has acquired the “H” signal from the first comparison unit sets the fluorescent tube unit control unit so that the fluorescent tube unit has a lower luminance, that is, the luminance indicated by the first normal voltage information. To drive. In addition, the first self-driving unit drives the power supply unit control unit so that the power supply unit has a low voltage direction, that is, a voltage indicated by the first normal voltage information. Similarly, it is assumed that the fluorescent tube voltage information acquired by the fluorescent tube voltage information acquisition unit is 450 Vrms. The first comparison unit compares the fluorescent tube unit voltage information 450 Vrms acquired by the fluorescent tube unit voltage information acquisition unit with the first normal voltage information 475 to 525 Vrms held by the first normal voltage information storage unit, and determines the fluorescent tube unit voltage. Since the information has a lower voltage value, an “L” signal is output to the first self-driving unit. The first self-driving unit that has acquired the “L” signal from the first comparison unit sets the fluorescent tube unit control unit so that the fluorescent tube unit has a high luminance, that is, the luminance indicated by the first normal voltage information. To drive. In addition, the first self-driving unit drives the power supply unit control unit so that the power supply unit becomes a high voltage, that is, the voltage indicated by the first normal voltage information. Furthermore, it is assumed that the fluorescent tube voltage information acquired by the fluorescent tube voltage information acquisition unit is 500 Vrms. The first comparison unit compares the fluorescent tube unit voltage information 500 Vrms acquired by the fluorescent tube unit voltage information acquisition unit with the first normal voltage information 475 to 525 Vrms held by the first normal voltage information holding unit, and determines the fluorescent tube unit voltage. Since the voltage value of the information is within the range of the first normal voltage information, no signal is output to the first self-driving unit. When no signal is acquired from the first comparison unit, the first self-driving unit does not drive the fluorescent tube control unit. That is, the current brightness of the fluorescent tube is maintained. Further, the first self-drive unit does not drive the power supply unit control unit. That is, the current voltage of the power supply unit is maintained.

(Fluorescent tube system)
The fluorescent tube system of this embodiment includes a fluorescent tube unit, a power supply unit, a fluorescent tube unit control unit, a power supply unit control unit, a fluorescent tube unit voltage information acquisition unit, a first normal voltage information holding unit, It has one comparison part and a first self-driving part. The fluorescent tube system according to the present embodiment monitors the tube voltage of the fluorescent tube unit to drive the fluorescent tube unit control unit and / or the power supply unit control unit in accordance with the detected tube voltage, so that the fluorescent tube unit or / And protect the power supply.

<Process flow>
The processing flow of the fluorescent tube system of this embodiment is shown below. The processing flow shown below can be implemented as a method, a program for causing a computer to execute, or a readable recording medium on which the program is recorded (this is the flow of other processing in this specification). Is the same).

FIG. 4 is a diagram illustrating a processing flow of the present embodiment.
First, in the first normal voltage information holding step, first normal voltage information that is information on a voltage that the fluorescent tube unit should have in a normal state is held in accordance with the control state of the fluorescent tube unit control unit (step S0401). Next, in the fluorescent tube section voltage information acquisition step, fluorescent tube section voltage information that is information indicating the voltage of the fluorescent tube section is acquired (step S0402). Next, it is determined whether there are a plurality of pieces of first normal voltage information held in the first normal voltage information holding step (step S0403). If there is a plurality of pieces of first normal voltage information, the process proceeds to step S0404. If there is not a plurality of pieces of first normal voltage information, the process proceeds to step S0405. Next, the selection comparing means selects specific first normal voltage information from among the plurality of first normal voltage information (step S0404). Next, a 1st comparison step compares the fluorescent tube part voltage information acquired by the fluorescent tube part voltage information acquisition step, and the 1st normal voltage information which a 1st normal voltage information holding step hold | maintains (step S0405). Next, in the first self-driving step, the fluorescent tube controller or / and the power supply controller are driven based on the comparison result in the first comparison step (step S0406).

(Example 1: mainly corresponding to claims 2 and 3)
Hereinafter, Example 1 of the present embodiment will be described. In Example 1, the first normal voltage information holding unit holds a plurality of first normal voltage information, and the first comparison unit acquires specific first normal voltage information from the plurality of first normal voltage information. It has a selective comparison means for performing comparison.

  FIG. 5 is a functional block diagram of the first embodiment. The fluorescent tube system 0500 of Example 1 includes a fluorescent tube unit 0501, a power supply unit 0502, a fluorescent tube unit control unit 0503, a power supply unit control unit 0504, a fluorescent tube unit voltage information acquisition unit 0505, and a first normal voltage. An information holding unit 0506, a first comparison unit 0507, a first self-driving unit 0508, and a user control unit 0513 (key input) are included. Further, the first comparison unit has a selection comparison unit 0509. The first normal voltage information holding unit includes a first reference voltage 0510, a second reference voltage 0511, and a third reference voltage 0512, which are a plurality of pieces of first normal voltage information. Although not shown in the figure, normally, the power supplied from the power supply unit is DC-AC converted and voltage converted by an inverter transformer or the like and supplied to the fluorescent tube unit. The inverter transformer may be configured to exist inside the power supply unit. The user control section is provided with setting keys and buttons for various controls, and the setting keys are provided as three positions of “bright”, “normal”, and “dark” with respect to the brightness of the backlight. By selecting the backlight brightness setting switch, a user control signal is output from the user control unit, and the selection comparison means according to the selection position of the setting switch of the user control unit is the first reference voltage, the second reference voltage or the third reference voltage. Switches the first normal voltage information of the reference voltage. The first reference voltage is selected for the “bright” setting, the second reference voltage is selected for the “normal” setting, and the third reference voltage is selected for the “dark” setting. The first reference voltage is set to the upper limit control limit voltage in the high luminance operation of the backlight, and the third reference voltage is set to the lower limit control limit voltage in the low luminance operation of the backlight. The fluorescent tube voltage information acquired by the fluorescent tube voltage information acquisition unit is compared with the first reference voltage, the second reference voltage, or the third reference voltage, which is the first normal voltage information, by the first comparison unit. The comparison result is output to the first self-driving unit. The first self-driving unit controls the fluorescent tube unit control unit and / or the power supply unit control unit based on the signal of the first comparison unit and the user control signal from the user control unit.

  FIG. 6 is a table illustrating an example of control of the first self-driving unit of the first embodiment. In the first comparison unit, the first reference voltage (corresponding to “bright”), which is the first normal voltage information, and the second reference voltage based on the signal that the user control signal from the user control unit is “bright” or “normal / dark” (Corresponding to “normal”) or a third reference voltage (corresponding to “dark”) is specified. The first comparison unit includes one reference voltage (e.g., a first reference voltage, that is, a signal indicating that the user control signal is “bright”) among a plurality of first normal voltage information specified by the user control signal, The fluorescent tube section voltage information is compared. As a result of the comparison, for example, when the voltage value of the fluorescent tube section voltage information is higher, the output of the first comparison section is “H”. In this case, the first self-driving unit outputs a control signal to the fluorescent tube control unit so as to change the duty in the low luminance direction. Here, “duty” refers to the ratio of “L” (or vice versa) to “H” of AC tube voltage applied in a pulsed manner to the fluorescent tube section. The duty is determined by a ratio of time of “H” and “L” during one period. When the fluorescent tube is lit when the tube voltage is “H”, the “H” time may be controlled to be shorter than the “L” time in order to reduce the luminance. Conversely, in order to achieve high brightness, the “H” time may be controlled to be longer than the “L” time. The first self-driving unit controls the power supply unit control unit in the direction of decreasing voltage. Control in the direction of decreasing voltage can be realized by controlling the power supply control unit in the direction of increasing the time constant of the power supply.

  Next, as a result of comparison in the first comparison unit, when the voltage value of the fluorescent tube unit voltage information is lower, the output of the first comparison unit becomes “L”. In this case, the first self-driving unit outputs a control signal to the fluorescent tube control unit, and performs control so as to change the duty in the high luminance direction. The first self-drive unit controls the power supply unit control unit in the direction of increasing the voltage. Control in the direction of increasing the voltage can be realized by controlling the power supply unit control unit in the direction of decreasing the time constant of the power supply unit.

  Next, if the voltage value of the fluorescent tube voltage information is within the first reference voltage as a result of comparison by the first comparison unit, the first comparison unit does not output. In this case, the first self-driving unit does not output the control signal to the fluorescent tube unit control unit, and the fluorescent tube unit maintains the current luminance. The first self-driving unit does not output a control signal to the power supply unit control unit, and the power supply unit maintains the current voltage.

  The case where the user control signal is “normal / dark” can be considered in the same manner as the case where the user control signal is “bright”.

      <Simple explanation of effect of Embodiment 1>

  According to the fluorescent tube system of the present embodiment, it is possible to control the voltage of the fluorescent tube and / or the power supply unit by acquiring the fluorescent tube unit voltage information and comparing it with the first normal voltage information. It is possible to detect an abnormal voltage in the fluorescent tube section and return the fluorescent tube system to a normal state.

<< Embodiment 2 >>
Hereinafter, a second embodiment of the fluorescent tube system of the present invention will be described.

<Concept of Embodiment 2>
The concept of this embodiment will be described below. The fluorescent tube system of the present embodiment monitors the voltage of the power supply unit to drive the fluorescent tube unit control unit or / and the power supply unit control unit in accordance with the detected tube voltage, and thereby the fluorescent tube unit or / and the power supply unit. It is characterized by protecting the part.

<Clarification of configuration requirements>
In the following, the configuration requirements of this embodiment will be clarified.
FIG. 7 is a functional block diagram of the fluorescent tube system of the present embodiment. The fluorescent tube system 0700 of this embodiment includes a fluorescent tube unit 0701, a power supply unit 0702, a fluorescent tube unit control unit 0703, a power supply unit control unit 0704, a power supply unit voltage information acquisition unit 0705, and second normal voltage information. The holding unit 0706, the second comparison unit 0707, and the second self-drive unit 0708 are included.

<Description of configuration requirements>
The configuration requirements of this embodiment will be described below.

(Fluorescent tube part), (Power supply part), (Fluorescent tube part control part), (Power supply part control part)
Since the fluorescent tube unit, the power supply unit, the fluorescent tube unit control unit, and the power supply unit control unit are the same as those in the first embodiment, description thereof will be omitted.

(Power supply voltage information acquisition unit)
The “power supply unit voltage information acquisition unit” acquires power supply unit voltage information. Here, the “power supply voltage information” refers to information indicating the voltage of the power supply. For example, a voltage value of 5 to 12 V corresponds to the power supply unit voltage information.

(Second normal voltage information holding unit)
The “second normal voltage information holding unit” holds second normal voltage information. Here, the “second normal voltage information” refers to information on the voltage that the power supply unit should have in a normal state according to the control state of the power supply unit control unit. Further, “according to the control state of the power supply unit control unit” means according to the voltage value controlled by the power supply unit control unit in accordance with the set voltage value. The “normal state” refers to a voltage value in a state within the set voltage range. As an example, the second normal voltage information corresponds to a voltage value within a range of 10 to 12V. The second normal voltage information may include information corresponding to the luminance of the fluorescent tube, for example, additional information such as “bright”, “normal”, and “dark”, in addition to the voltage value. Further, the second normal voltage information is not limited to a voltage value having a certain width regardless of time, but may be a voltage value related to time. The voltage value related to the time is not limited to the voltage value at a specific time, and may be a voltage value having a certain time width. For example, a voltage value having a width in one second may be used.

  The second normal voltage information holding unit can also hold a plurality of second normal voltage information corresponding to the control state. As an example, the second normal voltage information holding unit includes a plurality of first normal voltage information corresponding to the luminance of the fluorescent tube unit, for example, a plurality of voltages corresponding to luminances such as “bright”, “normal”, and “dark”. Can hold a value. In this case, it becomes possible to control the fluorescent tube section so as to have a suitable luminance in accordance with the use situation of a liquid crystal display or the like.

(Second comparison part)
The “second comparison unit” compares the power supply unit voltage information acquired by the power supply unit voltage information acquisition unit with the second normal voltage information held by the second normal voltage information holding unit. As an example, if the voltage value indicated by the power supply voltage information is higher than the voltage value in the range indicated by the second normal voltage information as a result of the comparison, the second comparison unit outputs an “H” signal. Output to the second self-driving unit. Further, as a result of the comparison, when the voltage value indicated by the power supply unit voltage information is lower than the voltage value in the range indicated by the second normal voltage information, the second comparison unit outputs the “L” signal to the second value. Outputs to the self-driving unit. Further, as a result of comparison, when the voltage value indicated by the power supply unit voltage information is within the voltage value range indicated by the second normal voltage information, the second comparison unit sends a signal to the second self-driving unit. No output (for example, high impedance state). The output of the second comparison unit may be digital data output.

  Further, when the second normal voltage information holding unit holds a plurality of second normal voltage information according to the control state, the second comparison unit determines a specific first value from the plurality of second normal voltage information according to the control state. It is also possible to employ a configuration having selection / comparison means for acquiring and comparing two normal voltage information. As an example, the second normal voltage information holding unit has a plurality of voltage values corresponding to luminances such as “bright”, “normal”, “dark” as a plurality of second normal voltage information corresponding to the luminance of the fluorescent tube unit. Is stored, the selection / comparison unit can acquire and compare the second normal voltage information corresponding to “bright”. The acquisition of the specific second normal voltage information may be acquired manually from the outside of the fluorescent tube system by key input or the like, or may be acquired from a memory such as a ROM set in advance inside the fluorescent tube system. When the selective comparison means acquires specific information from a plurality of second normal voltage information preset in the fluorescent tube system, it is specified so that the luminance of the fluorescent tube can be automatically changed according to the time zone. It is also possible to acquire the second normal voltage information. For example, “normal” or “dark” can be selected during relatively strong sunlight from morning to evening, and “bright” can be selected during nighttime when there is no sunlight. it can.

(Second self-driving part)
The “second self-driving unit” drives the fluorescent tube unit control unit and / or the power source unit control unit based on the comparison result in the second comparison unit. Here, “based on the comparison result” means that the fluorescent tube control unit and / or the power supply control unit is driven in accordance with the signal output from the second comparison unit. Here, “drive” means to drive the fluorescent tube control unit or / and the power supply control unit so that the fluorescent tube unit or / and the power supply unit have a predetermined voltage. “Predetermined voltage” refers to a voltage set when designing a fluorescent tube system. As an example, when the output from the second comparison unit is “H”, the second self-driving unit drives the fluorescent tube control unit so that the fluorescent tube unit has low luminance. Or you may drive a fluorescent tube control part so that the voltage of a fluorescent tube part may be interrupted | blocked. Further, as an example, when the output from the second comparison unit is “H”, the first self-driving unit drives the power supply unit control unit so that the power supply unit has a low voltage. Or you may drive a power supply control part so that the voltage of a power supply part may be interrupted | blocked.

  FIG. 8 is a table showing an example of control of the second self-driving unit. For example, it is assumed that the second normal voltage information holding unit holds a voltage value of 10 to 12V. At this time, it is assumed that the power supply voltage information acquired by the power supply voltage information acquisition unit is 13V. The second comparison unit compares the power supply unit voltage information 13V acquired by the power supply unit voltage information acquisition unit with the second normal voltage information 10-12V held by the second normal voltage information holding unit, Since the voltage value is high, an “H” signal is output to the second self-driving unit. The second self-driving unit that has acquired the “H” signal from the second comparison unit sets the fluorescent tube unit control unit so that the fluorescent tube unit has a lower luminance, that is, the luminance indicated by the second normal voltage information. To drive. In addition, the second self-driving unit drives the power supply unit control unit so that the power supply unit has a low voltage direction, that is, a voltage indicated by the second normal voltage information. Similarly, it is assumed that the power supply unit voltage information acquired by the power supply unit voltage information acquisition unit is 9V. The second comparison unit compares the power supply unit voltage information 9V acquired by the power supply unit voltage information acquisition unit with the second normal voltage information 10-12V held by the second normal voltage information storage unit, Since the voltage value is low, an “L” signal is output to the second self-driving unit. The second self-drive unit that has acquired the “L” signal from the second comparison unit sets the fluorescent tube unit control unit so that the fluorescent tube unit has a high luminance, that is, the luminance indicated by the second normal voltage information. To drive. In addition, the second self-driving unit drives the power supply unit control unit so that the power supply unit becomes a high voltage, that is, the voltage indicated by the second normal voltage information. Furthermore, it is assumed that the power supply voltage information acquired by the power supply voltage information acquisition unit is 11V. The second comparison unit compares the power supply unit voltage information 11V acquired by the power supply unit voltage information acquisition unit with the second normal voltage information 10-12V held by the second normal voltage information holding unit, and determines the voltage of the power supply unit voltage information. Since the value is within the range of the second normal voltage information, no signal is output to the second self-driving unit. When no signal is acquired from the second comparison unit, the second self-driving unit does not drive the fluorescent tube control unit. That is, the current brightness of the fluorescent tube is maintained. Further, the second self-driving unit does not drive the power supply unit control unit. That is, the current voltage of the power supply unit is maintained.

(Fluorescent tube system)
The fluorescent tube system of the present embodiment includes a fluorescent tube unit, a power supply unit, a fluorescent tube unit control unit, a power supply unit control unit, a power supply unit voltage information acquisition unit, a second normal voltage information holding unit, and a second It has a comparison part and a 2nd self-drive part. The fluorescent tube system of the present embodiment monitors the tube voltage of the power supply unit, and drives the fluorescent tube unit control unit or / and the power supply unit control unit according to the detected power supply unit voltage. And protect the power supply.

<Process flow>
The processing flow of the fluorescent tube system of this embodiment is shown below.

FIG. 9 is a diagram showing the flow of processing of this embodiment.
First, in the second normal voltage information holding step, second normal voltage information, which is information on a voltage that the power supply unit should have in a normal state, according to the control state of the power supply unit control unit is held (step S0901). Next, in the power supply unit voltage information acquisition step, power supply unit voltage information that is information indicating the voltage of the power supply unit is acquired (step S0902). Next, it is determined whether there are a plurality of pieces of second normal voltage information held in the second normal voltage information holding step (step S0903). If there is a plurality of pieces of second normal voltage information, the process proceeds to step S0904. If there is not a plurality of pieces of second normal voltage information, the process proceeds to step S0905. Next, the selection comparison means selects specific second normal voltage information from among the plurality of second normal voltage information (step S0904). Next, the second comparison step compares the power supply unit voltage information acquired by the power supply unit voltage information acquisition step with the second normal voltage information held by the second normal voltage information holding step (step S0905). Next, in the second self-driving step, the fluorescent tube controller or / and the power supply controller are driven based on the comparison result in the second comparison step (step S0906).

(Example 2: Mainly corresponding to claims 5 and 6)
Hereinafter, Example 2 of the present embodiment will be described. In the second embodiment, the second normal voltage information holding unit holds a plurality of second normal voltage information, and the second comparison unit acquires specific second normal voltage information from the plurality of second normal voltage information. It has a selective comparison means for performing comparison.

  FIG. 10 is a functional block diagram of the second embodiment. The fluorescent tube system 1000 according to the second embodiment includes a fluorescent tube unit 1001, a power supply unit 1002, a fluorescent tube unit control unit 1003, a power supply unit control unit 1004, a power supply unit voltage information acquisition unit 1005, and second normal voltage information. It comprises a holding unit 1006, a second comparison unit 1007, a second self-driving unit 1008, and a user control unit 1013 (key input). In addition, the second comparison unit includes selection comparison means 1009. The second normal voltage information holding unit has a first reference voltage 1010, a second reference voltage 1011 and a third reference voltage 1012 which are a plurality of second normal voltage information. Although not shown in the figure, normally, the power supplied from the power supply unit is DC-AC converted and voltage converted by an inverter transformer or the like and supplied to the fluorescent tube unit. The inverter transformer may be configured to exist inside the power supply unit. The user control section is provided with setting keys and buttons for various controls, and the setting keys are provided as three positions of “bright”, “normal”, and “dark” with respect to the brightness of the backlight. By selecting the backlight brightness setting switch, a user control signal is output from the user control unit, and the selection comparison means according to the selection position of the setting switch of the user control unit is the first reference voltage, the second reference voltage or the third reference voltage. Switches the second normal voltage information of the reference voltage. The first reference voltage is selected for the “bright” setting, the second reference voltage is selected for the “normal” setting, and the third reference voltage is selected for the “dark” setting. The first reference voltage is set to the upper limit control limit voltage in the high luminance operation of the backlight, and the third reference voltage is set to the lower limit control limit voltage in the low luminance operation of the backlight. Further, the power supply voltage information acquired by the power supply voltage information acquisition unit is compared with the first reference voltage, the second reference voltage, or the third reference voltage, which is the second normal voltage information, in the second comparison unit. The result is output to the second self-driving unit. The second self-driving unit controls the fluorescent tube unit control unit and / or the power supply unit control unit based on the signal of the second comparison unit and the user control signal from the user control unit.

  FIG. 11 is a table illustrating an example of control of the second self-driving unit of the second embodiment. In the second comparison unit, the first reference voltage (corresponding to “bright”), which is the second normal voltage information, according to the signal that the user control signal from the user control unit is “bright” or “normal / dark”, the second reference voltage (Corresponding to “normal”) or a third reference voltage (corresponding to “dark”) is specified. The second comparison unit includes one reference voltage among the plurality of second normal voltage information specified by the user control signal (for example, when the first reference voltage, that is, the user control signal is a “bright” signal), The power supply voltage information is compared. As a result of the comparison, for example, when the voltage value of the power supply unit voltage information is higher, the output of the second comparison unit becomes “H”. In this case, the second self-driving unit outputs a control signal to the fluorescent tube control unit so as to change the duty in the low luminance direction. When the fluorescent tube is lit when the tube voltage is “H”, the “H” time may be controlled to be shorter than the “L” time in order to reduce the luminance. Conversely, in order to achieve high brightness, the “H” time may be controlled to be longer than the “L” time. The second self-driving unit controls the power supply unit control unit in the direction of decreasing voltage. Control in the direction of decreasing voltage can be realized by controlling the power supply control unit in the direction of increasing the time constant of the power supply.

  Next, as a result of comparison in the second comparison unit, when the voltage value of the fluorescent tube unit voltage information is lower, the output of the second comparison unit becomes “L”. In this case, the second self-driving unit outputs a control signal to the fluorescent tube control unit, and performs control so as to change the duty in the high luminance direction. The second self-driving unit controls the power supply unit control unit in the direction of increasing the voltage. Control in the direction of increasing the voltage can be realized by controlling the power supply unit control unit in the direction of decreasing the time constant of the power supply unit.

  Next, as a result of comparison by the second comparison unit, when the voltage value of the power supply unit voltage information is within the range of the first reference voltage, the second comparison unit does not output. In this case, the second self-driving unit does not output the control signal to the fluorescent tube unit control unit, and the fluorescent tube unit maintains the current luminance. The second self-driving unit does not output a control signal to the power supply unit control unit, and the power supply unit maintains the current voltage.

  The case where the user control signal is “normal / dark” can be considered in the same manner as the case where the user control signal is “bright”.

      <Simple explanation of effect of embodiment 2>

  According to the fluorescent tube system of the present embodiment, the voltage of the fluorescent tube and / or the power supply unit can be controlled by acquiring the power supply unit voltage information and comparing it with the second normal voltage information. It is possible to detect the abnormal voltage of the unit and return the fluorescent tube system to a normal state.

<< Embodiment 3 >>
The third embodiment of the fluorescent tube system of the present invention will be described below.

<Concept of Embodiment 3>
The concept of this embodiment will be described below. The fluorescent tube system of the present embodiment monitors the tube voltage of the fluorescent tube unit and the voltage in the transient state, so that the fluorescent tube unit control unit and / or the power supply unit control unit are selected according to the detected tube voltage and the transient state voltage. To protect the fluorescent tube part and / or the power supply part.

<Clarification of configuration requirements>
In the following, the configuration requirements of this embodiment will be clarified.
FIG. 12 is a functional block diagram of the fluorescent tube system of the present embodiment. The fluorescent tube system 1200 of this embodiment includes a fluorescent tube unit 1201, a power supply unit 1202, a fluorescent tube unit control unit 1203, a power supply unit control unit 1204, a fluorescent tube unit voltage information acquisition unit 1205, and a first normal voltage. An information holding unit 1206, a first comparison unit 1207, a third self-driving unit 1208, a transient state voltage information acquisition unit 1209, a third normal voltage information holding unit 1210, and a third comparison unit 1211 are included.

<Description of configuration requirements>
The configuration requirements of this embodiment will be described below.

(Fluorescent tube section), (Power supply section), (Fluorescent tube section control section), (Power supply section control section), (Fluorescent tube section voltage information acquisition section), (First normal voltage information holding section), (First comparison) Part)
Since the fluorescent tube unit, the power supply unit, the fluorescent tube unit control unit, the power supply unit control unit, the fluorescent tube unit voltage information acquisition unit, the first normal voltage information holding unit, and the first comparison unit are the same as those in the first embodiment, they will be described. Is omitted.

(Transient state voltage information acquisition unit)
The “transient state voltage information acquisition unit” acquires transient state voltage information. Here, “transient state voltage information” refers to information indicating the transient state voltage of the fluorescent tube section. Here, the “transient state” refers to a state in a transition period until the fluorescent tube portion exhibits a constant voltage characteristic when the power is turned on. As described in the fluorescent tube portion of the first embodiment, as an example, when a fluorescent tube portion having a tube voltage of about 300 to 1300 Vrms is used, a voltage of about 500 to 1600 Vrms until the tube voltage is shown is transient. It becomes the voltage of the state (normal case).

FIG. 28 is a diagram for explaining the transient state voltage information. In FIG. 28, the voltage up to the current I ₀ (A) until the tube voltage reaches 300 to 1300 Vrms indicates the transient state voltage, and the voltage value of 500 to 1600 Vrms corresponds.

(Third normal voltage information holding unit)
The “third normal voltage information holding unit” holds third normal voltage information. Here, “third normal voltage information” refers to information indicating a voltage in a transient state that the fluorescent tube portion should have in a normal state. As described in the fluorescent tube section of the first embodiment, the third normal voltage information includes, as an example, a voltage of about 500 to 1600 Vrms when a fluorescent tube section with a tube voltage of about 300 to 1300 Vrms is used. To do. Note that there may be a plurality of pieces of third normal voltage information according to a control state by a user control signal from the outside.

(Third comparison part)
The “third comparison unit” compares the transient state voltage information acquired by the transient state voltage information acquisition unit with the third normal voltage information held by the third normal voltage information holding unit. As an example, when the voltage value indicated by the transient state voltage information is higher than the voltage value in the range indicated by the third normal voltage information, the third comparison unit outputs an “H” signal. Output to the third self-driving unit. As a result of the comparison, when the voltage value indicated by the transient state voltage information is lower than the voltage value in the range indicated by the third normal voltage information, the third comparison unit outputs the “L” signal to the third value. Outputs to the self-driving unit. Further, as a result of comparison, when the voltage value indicated by the transient state voltage information is within the range of the voltage value indicated by the third normal voltage information, the third comparison unit sends the signal to the third self-driving unit. No output (for example, high impedance state). The output of the third comparison unit may be digital data.

(Third self-driving unit)
The third self-driving unit drives the fluorescent tube unit control unit and / or the power supply unit control unit based on the comparison result in the third comparison unit and the comparison result in the first comparison unit. Here, “based on the comparison result” means that the fluorescent tube controller or / and the power supply controller are driven in accordance with signals output from the third comparator and the first comparator. Here, “drive” means to drive the fluorescent tube control unit or / and the power supply control unit so that the fluorescent tube unit or / and the power supply unit have a predetermined voltage. “Predetermined voltage” refers to a voltage set when designing a fluorescent tube system. Specific examples of the control of the third self-driving unit are shown in FIGS. 15, 16, and 17 to be described later.

(Fluorescent tube system)
The fluorescent tube system of this embodiment includes a fluorescent tube unit, a power supply unit, a fluorescent tube unit control unit, a power supply unit control unit, a fluorescent tube unit voltage information acquisition unit, a first normal voltage information holding unit, A comparison unit, a third self-driving unit, a transient state voltage information acquisition unit, a third normal voltage information holding unit, and a third comparison unit; The fluorescent tube system of the present embodiment monitors the tube voltage of the fluorescent tube unit and the voltage in the transient state, so that the fluorescent tube unit control unit and / or the power supply unit control unit are selected according to the detected tube voltage and the transient state voltage. To protect the fluorescent tube section and / or the power supply section.

<Process flow>
The processing flow of the fluorescent tube system of this embodiment is shown below.

FIG. 13 is a diagram illustrating a processing flow of the present embodiment.
First, in the first normal voltage information holding step, first normal voltage information, which is information on a voltage that the fluorescent tube unit should have in a normal state, according to the control state of the fluorescent tube unit control unit is held (step S1301). Next, in the fluorescent tube section voltage information acquisition step, fluorescent tube section voltage information that is information indicating the voltage of the fluorescent tube section is acquired (step S1302). Next, it is determined whether there are a plurality of pieces of first normal voltage information held in the first normal voltage information holding step (step S1303). If there is a plurality of pieces of first normal voltage information, the process proceeds to step S1304. If there is not a plurality of pieces of first normal voltage information, the process proceeds to step S1305. Next, the selection comparison means selects specific first normal voltage information from among the plurality of first normal voltage information (step S1304). Next, a 1st comparison step compares the fluorescent tube part voltage information acquired by the fluorescent tube part voltage information acquisition step, and the 1st normal voltage information which a 1st normal voltage information holding step hold | maintains (step S1305). Next, in the third normal voltage information holding step, third normal voltage information which is information indicating a voltage in a transient state that the fluorescent tube portion should have in a normal state is held (step S1306). Next, the transient state voltage information acquisition unit acquires transient state voltage information that is information indicating the voltage in the transient state of the fluorescent tube unit (step S1307). Next, the third comparison unit compares the transient state voltage information acquired by the transient state voltage information acquisition unit with the third normal voltage information held by the third normal voltage information holding unit (step S1308). Next, the third self-driving unit drives the fluorescent tube unit control unit and / or the power source unit control unit based on the comparison result in the third comparison unit and the comparison result in the first comparison unit (step S1309).

(Example 3: mainly corresponding to claim 7)
Hereinafter, Example 3 of the present embodiment will be described.

  FIG. 14 is a functional block diagram of the third embodiment. The fluorescent tube system 1400 according to the third embodiment includes a fluorescent tube unit 1401, a power supply unit 1402, a fluorescent tube unit control unit 1403, a power supply unit control unit 1404, a fluorescent tube unit voltage information acquisition unit 1405, and a first normal voltage. Information holding unit 1406, first comparison unit 1407, third self-driving unit 1408, transient state voltage information acquisition unit 1414, third normal voltage information holding unit 1415, third comparison unit 1416, user control unit 1413 (key input). Further, the first comparison unit has a selection comparison unit 1409. The first normal voltage information holding unit has a first reference voltage 1410, a second reference voltage 1411, and a third reference voltage 1412, which are a plurality of first normal voltage information. Although not shown in the figure, normally, the power supplied from the power supply unit is DC-AC converted and voltage converted by an inverter transformer or the like and supplied to the fluorescent tube unit. The inverter transformer may be configured to exist inside the power supply unit. The user control section is provided with setting keys and buttons for various controls, and the setting keys are provided as three positions of “bright”, “normal”, and “dark” with respect to the brightness of the backlight. By selecting the backlight brightness setting switch, a user control signal is output from the user control unit, and the selection comparison means according to the selection position of the setting switch of the user control unit has a first reference voltage (corresponding to “bright”), The first normal voltage information of the second reference voltage (corresponding to “normal”) or the third reference voltage (corresponding to “dark”) is switched. The first reference voltage is selected for the “bright” setting, the second reference voltage is selected for the “normal” setting, and the third reference voltage is selected for the “dark” setting. The first reference voltage is set to the upper limit control limit voltage in the high luminance operation of the backlight, and the third reference voltage is set to the lower limit control limit voltage in the low luminance operation of the backlight. The fluorescent tube voltage information acquired by the fluorescent tube voltage information acquisition unit is compared with the first reference voltage, the second reference voltage, or the third reference voltage, which is the first normal voltage information, by the first comparison unit. The comparison result is output to the third self-driving unit. The third comparison unit compares the transient state voltage information acquired by the transient state voltage information acquisition unit with the third normal voltage information held by the third normal voltage information holding unit. The comparison result is output to the third self-driving unit. The third self-driving unit controls the fluorescent tube unit control unit and / or the power unit control unit based on the signal from the third comparison unit, the signal from the first comparison unit, and the user control signal from the user control unit. To do.

  15, FIG. 16, and FIG. 17 are tables showing an example of control of the third self-driving unit of the third embodiment. The fluorescent tube section voltage information is compared with the first reference voltage, the second reference voltage, or the third reference voltage by the first comparison section, and the comparison result is input to the third self-driving section. The transient state voltage information is compared with the third normal voltage information by the third comparison unit, and the comparison result by the third comparison unit is input to the third self-driving unit. Based on the signal from the third comparison unit, the signal from the first comparison unit, and the user control signal from the user control unit, the third self-driving unit controls the fluorescent tube unit control unit and / or the power supply unit control unit. Control. In the third self-driving unit, “H”, “L” output or “no output” of the first comparison unit, a signal that the user control signal is “bright” or “normal / dark”, and “H” of the third comparison unit ”,“ L ”output or“ no output ”, the fluorescent tube control unit and / or the power supply control unit are controlled.

  FIG. 15 shows a case where the output of the first comparison unit is “H”. For example, when the output of the first comparison unit is “H”, the user control signal is “bright”, and the output of the third comparison unit is “H”, the third self-driving unit controls the fluorescent tube unit. The control is performed so that the duty is changed in the low luminance direction, and the power supply control unit is controlled in the cutoff direction (that is, the power supply is shut down when the specified voltage is not reached within a certain period). . In addition, when the output of the first comparison unit is “H”, the user control signal is “bright”, and the output of the third comparison unit is “L”, the third self-driving unit controls the fluorescent tube unit. The power supply unit control unit is controlled to immediately shut off (OFF) the power supply. When the output of the first comparison unit is “H”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”, the third self-driving unit The fluorescent tube control unit is controlled to change the duty in the low luminance direction, and the power supply control unit is controlled to maintain power supply.

  When the output of the first comparison unit is “H”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “H”, the third self-driving unit The unit control unit is further controlled to change the duty in the low luminance direction, and the power source control unit is controlled to be shut off. When the output of the first comparison unit is “H”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “L”, the third self-driving unit The unit control unit is controlled to be cut off (OFF), and the power supply unit control unit is controlled to be immediately cut off (OFF). Also, if the output of the first comparison unit is “H”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “no output (normal)”, the third self-driving unit Controls the fluorescent tube unit control unit to change the duty in the low luminance direction, and controls the power source unit control unit to maintain the power supply.

  FIG. 16 shows a case where the output of the first comparison unit is “L”. For example, when the output of the first comparison unit is “L”, the user control signal is “bright”, and the output of the third comparison unit is “H”, the third self-driving unit controls the fluorescent tube unit. Control is performed so as to maintain the state as it is, and the power source control unit is controlled to be shut off. In addition, when the output of the first comparison unit is “L”, the user control signal is “bright”, and the output of the third comparison unit is “L”, the third self-driving unit controls the fluorescent tube unit. The power supply unit control unit is controlled to immediately shut off (OFF) the power supply. When the output of the first comparison unit is “L”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”, the third self-driving unit The fluorescent tube control unit is controlled to change the duty in the low luminance direction, and the power supply control unit is controlled to be shut off.

  When the output of the first comparison unit is “L”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “H”, the third self-driving unit The unit control unit is controlled to maintain the state as it is, and the power source unit control unit is controlled to be shut off. When the output of the first comparison unit is “L”, the user control signal is “normal / dark”, and the output of the third comparison unit is “L”, the third self-driving unit The unit control unit is controlled to be cut off (OFF), and the power supply unit control unit is controlled to be immediately cut off (OFF). Further, when the output of the first comparison unit is “L”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “no output (normal)”, the third self-driving unit Controls the fluorescent tube unit control unit to change the duty in the low luminance direction, and controls the power source unit control unit to shut off.

  FIG. 17 shows a case where the output of the first comparison unit is “no output (normal)”. For example, when the output of the first comparison unit is “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “H”, the third self-drive unit is The fluorescent tube control unit is controlled to maintain the same state, and the power supply unit control unit is controlled to maintain the same state. In addition, when the output of the first comparison unit is “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “L”, the third self-drive unit The fluorescent tube control unit is controlled to maintain the state as it is, and the power supply control unit is controlled to immediately shut off (OFF) the power supply. In addition, if the output of the first comparison unit is “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”, the third self The drive unit controls the fluorescent tube unit control unit so as to maintain the state as it is, and controls the power source unit control unit so as to maintain the state as it is.

  In addition, when the output of the first comparison unit is “no output (normal)”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “H”, the third self-driving unit Controls the fluorescent tube control unit to maintain the state as it is, and controls the power source control unit to maintain the state as it is. Further, when the output of the first comparison unit is “no output (normal)”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “L”, the third self-driving unit Controls the fluorescent tube control unit so as to maintain the state as it is, and controls the power supply control unit so that the power supply is immediately shut off (OFF). Also, if the output of the first comparator is “No output (normal)”, the user control signal is “Normal / Dark” and the output of the third comparator is “No output (Normal)”, The three self-driving units control the fluorescent tube unit control unit so as to maintain the state as it is, and control the power source unit control unit so as to maintain the state as it is.

  In addition, according to the configuration of this fluorescent tube system, it is possible to input not only the protection of the backlight but also a circuit involving load fluctuations such as voice changes and circuit conditions that change the load due to key operations (by user control) to the control unit. It is possible to eliminate fuses in all input stages of the product.

      <Simple explanation of effect of Embodiment 3>

  According to the fluorescent tube system of the present embodiment, the voltage of the fluorescent tube and / or the power supply unit can be controlled based on the output results of the third comparison unit and the first comparison unit. It is possible to detect the voltage and return the fluorescent tube system to a normal state.

  << Embodiment 4 >>

<Concept of Embodiment 4>
The concept of this embodiment will be described below. The fluorescent tube system of the present embodiment monitors the voltage of the power supply unit and the transient voltage of the fluorescent tube unit, thereby controlling the fluorescent tube unit according to the detected voltage of the power supply unit and the transient voltage of the fluorescent tube unit. And / or the power source control unit is driven to protect the fluorescent tube unit and / or the power source unit.

<Clarification of configuration requirements>
In the following, the configuration requirements of this embodiment will be clarified.
FIG. 18 is a functional block diagram of the fluorescent tube system of the present embodiment. The fluorescent tube system 1800 of this embodiment includes a fluorescent tube unit 1801, a power supply unit 1802, a fluorescent tube unit control unit 1803, a power supply unit control unit 1804, a power supply unit voltage information acquisition unit 1805, and second normal voltage information. A holding unit 1806, a second comparison unit 1807, a fourth self-drive unit 1808, a transient state voltage information acquisition unit 1809, a third normal voltage information holding unit 1810, and a third comparison unit 1811 are included.

<Description of configuration requirements>
The configuration requirements of this embodiment will be described below.

(Fluorescent tube part), (Power supply part), (Fluorescent tube part control part), (Power supply part control part), (Power supply part voltage information acquisition part), (Second normal voltage information holding part), (Second comparison part) )
Since the fluorescent tube unit, the power supply unit, the fluorescent tube unit control unit, the power supply unit control unit, the power supply unit voltage information acquisition unit, the second normal voltage information holding unit, and the second comparison unit are the same as those in the second embodiment, a description will be given. Omitted.

(Transient state voltage information acquisition unit), (Third normal voltage information holding unit), (Third comparison unit)
Since the transient state voltage information acquisition unit, the third normal voltage information holding unit, and the third comparison unit are the same as those in the third embodiment, description thereof is omitted.

(Fourth self-driving part)
The fourth self-drive unit drives the fluorescent tube unit control unit and / or the power supply unit control unit based on the comparison result in the third comparison unit and the comparison result in the second comparison unit. Here, “based on the comparison result” means that the fluorescent tube controller or / and the power supply controller are driven in accordance with the signals output from the third comparator and the second comparator. Here, “drive” means to drive the fluorescent tube control unit or / and the power supply control unit so that the fluorescent tube unit or / and the power supply unit have a predetermined voltage. “Predetermined voltage” refers to a voltage set when designing a fluorescent tube system. Specific examples of the control of the fourth self-driving unit are shown in FIGS. 21, 22, and 23 described later.

(Fluorescent tube system)
The fluorescent tube system of the present embodiment includes a fluorescent tube unit, a power supply unit, a fluorescent tube unit control unit, a power supply unit control unit, a power supply unit voltage information acquisition unit, a second normal voltage information holding unit, and a second A comparison unit; a fourth self-drive unit; a transient state voltage information acquisition unit; a third normal voltage information holding unit; and a third comparison unit. The fluorescent tube system of the present embodiment monitors the voltage of the power supply unit and the transient voltage of the fluorescent tube unit, thereby controlling the fluorescent tube unit according to the detected voltage of the power supply unit and the transient voltage of the fluorescent tube unit. And / or the power supply control unit are driven to protect the fluorescent tube part and / or the power supply part.

<Process flow>
The processing flow of the fluorescent tube system of this embodiment is shown below.

FIG. 19 is a diagram showing the flow of processing of this embodiment.
First, in the second normal voltage information holding step, second normal voltage information that is information on a voltage that the power supply unit should have in a normal state is held in accordance with the control state of the power supply unit control unit (step S1901). Next, in the power supply unit voltage information acquisition step, power supply unit voltage information that is information indicating the voltage of the power supply unit is acquired (step S1902). Next, it is determined whether there are a plurality of pieces of second normal voltage information held in the second normal voltage information holding step (step S1903). If there is a plurality of pieces of second normal voltage information, the process proceeds to step S1904. If there is no second normal voltage information, the process proceeds to step S1905. Next, the selection comparison means selects specific second normal voltage information from among the plurality of second normal voltage information (step S1904). Next, in the second comparison step, the power supply unit voltage information acquired in the power supply unit voltage information acquisition step is compared with the second normal voltage information held in the second normal voltage information holding step (step S1905). Next, in the third normal voltage information holding step, third normal voltage information which is information indicating a voltage in a transient state that the fluorescent tube unit should have in a normal state is held (step S1906). Next, the transient state voltage information acquisition unit acquires transient state voltage information, which is information indicating the transient state voltage of the fluorescent tube unit (step S1907). Next, the third comparison unit compares the transient state voltage information acquired by the transient state voltage information acquisition unit with the third normal voltage information held by the third normal voltage information holding unit (step S1908). Next, the fourth self-driving unit drives the fluorescent tube control unit and / or the power source control unit based on the comparison result in the third comparison unit and the comparison result in the second comparison unit (step S1909).

(Example 4: mainly corresponding to claim 8)
Example 4 of the present embodiment will be described below.

  FIG. 20 is a functional block diagram of the fourth embodiment. The fluorescent tube system 2000 according to the fourth embodiment includes a fluorescent tube unit 2001, a power supply unit 2002, a fluorescent tube unit control unit 2003, a power supply unit control unit 2004, a power supply unit voltage information acquisition unit 2005, and second normal voltage information. Holding unit 2006, second comparison unit 2007, fourth self-drive unit 2008, transient state voltage information acquisition unit 2014, third normal voltage information holding unit 2015, third comparison unit 2016, and user control unit 2013 (Key input). The second comparison unit includes selection comparison means 2009. The second normal voltage information holding unit includes a first reference voltage 2010, a second reference voltage 2011, and a third reference voltage 2012, which are a plurality of second normal voltage information. Although not shown in the figure, normally, the power supplied from the power supply unit is DC-AC converted and voltage converted by an inverter transformer or the like and supplied to the fluorescent tube unit. The inverter transformer may be configured to exist inside the power supply unit. The user control section is provided with setting keys and buttons for various controls, and the setting keys are provided as three positions of “bright”, “normal”, and “dark” with respect to the brightness of the backlight. By selecting the backlight brightness setting switch, a user control signal is output from the user control unit, and the selection comparison means according to the selection position of the setting switch of the user control unit has a first reference voltage (corresponding to “bright”), The second normal voltage information of the second reference voltage (corresponding to “normal”) or the third reference voltage (corresponding to “dark”) is switched. The first reference voltage is selected for the “bright” setting, the second reference voltage is selected for the “normal” setting, and the third reference voltage is selected for the “dark” setting. The first reference voltage is set to the upper limit control limit voltage in the high luminance operation of the backlight, and the third reference voltage is set to the lower limit control limit voltage in the low luminance operation of the backlight. Further, the power supply voltage information acquired by the power supply voltage information acquisition unit is compared with the first reference voltage, the second reference voltage, or the third reference voltage, which is the second normal voltage information, in the second comparison unit. The result is output to the fourth self-driving unit. The third comparison unit compares the transient state voltage information acquired by the transient state voltage information acquisition unit with the third normal voltage information held by the third normal voltage information holding unit. The comparison result is output to the fourth self-driving unit. The fourth self-drive unit controls the fluorescent tube control unit and / or the power supply control unit based on the signal from the third comparison unit, the signal from the second comparison unit, and the user control signal from the user control unit. To do.

  21, 22, and 23 are tables illustrating an example of control of the fourth self-drive unit of the fourth embodiment. The power supply unit voltage information is compared with the first reference voltage, the second reference voltage, or the third reference voltage by the second comparison unit, and the comparison result is input to the fourth self-drive unit. The transient state voltage information is compared with the third normal voltage information by the third comparison unit, and the comparison result by the third comparison unit is input to the third self-driving unit. Based on the signal from the third comparison unit, the signal from the second comparison unit, and the user control signal from the user control unit, the third self-driving unit controls the fluorescent tube unit control unit and / or the power supply unit control unit. Control. In the fourth self-driving unit, “H”, “L” output or “no output” of the second comparison unit, “bright” or “normal / dark” signal of the user control signal, and “H” of the third comparison unit ”,“ L ”output or“ no output ”, the fluorescent tube control unit and / or the power supply control unit are controlled.

  FIG. 21 shows a case where the output of the second comparison unit is “H”. For example, when the output of the second comparison unit is “H”, the user control signal is “bright”, and the output of the third comparison unit is “H”, the fourth self-drive unit controls the fluorescent tube unit. The control is performed so that the duty is changed in the low luminance direction, and the power supply control unit is controlled in the cutoff direction (that is, the power supply is shut down when the specified voltage is not reached within a certain period). . Further, when the output of the second comparison unit is “H”, the user control signal is “bright”, and the output of the third comparison unit is “L”, the fourth self-drive unit controls the fluorescent tube unit. The power supply unit control unit is controlled to immediately shut off (OFF) the power supply. Further, when the output of the second comparison unit is “H”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”, the fourth self-drive unit is The fluorescent tube control unit is controlled to change the duty in the low luminance direction, and the power supply control unit is controlled to maintain power supply.

  When the output of the second comparison unit is “H”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “H”, the fourth self-driving unit The unit control unit is further controlled to change the duty in the low luminance direction, and the power source control unit is controlled to be shut off. Further, when the output of the second comparison unit is “H”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “L”, the fourth self-driving unit The unit control unit is controlled to be cut off (OFF), and the power supply unit control unit is controlled to be immediately cut off (OFF). Also, if the output of the second comparison unit is “H”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “no output (normal)”, the fourth self-driving unit Controls the fluorescent tube unit control unit to change the duty in the low luminance direction, and controls the power source unit control unit to maintain the power supply.

  FIG. 22 shows a case where the output of the second comparison unit is “L”. For example, if the output of the second comparison unit is “L”, the user control signal is “bright”, and the output of the third comparison unit is “H”, the fourth self-drive unit controls the fluorescent tube unit. Control is performed so as to maintain the state as it is, and the power source control unit is controlled to be shut off. Further, when the output of the second comparison unit is “L”, the user control signal is “bright”, and the output of the third comparison unit is “L”, the fourth self-drive unit controls the fluorescent tube unit. The power supply unit control unit is controlled to immediately shut off (OFF) the power supply. When the output of the second comparison unit is “L”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”, the fourth self-driving unit The fluorescent tube control unit is controlled to change the duty in the low luminance direction, and the power supply control unit is controlled to be shut off.

  When the output of the second comparison unit is “L”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “H”, the fourth self-driving unit The unit control unit is controlled to maintain the state as it is, and the power source unit control unit is controlled to be shut off. Further, when the output of the second comparison unit is “L”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “L”, the fourth self-driving unit The unit control unit is controlled to be cut off (OFF), and the power supply unit control unit is controlled to be immediately cut off (OFF). If the output of the second comparison unit is “L”, the user control signal is “normal / dark”, and the output of the third comparison unit is “no output (normal)”, the fourth self-driving unit Controls the fluorescent tube unit control unit to change the duty in the low luminance direction, and controls the power source unit control unit to shut off.

  FIG. 23 shows a case where the output of the second comparison unit is “no output (normal)”. For example, when the output of the second comparison unit is “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “H”, the fourth self-drive unit is The fluorescent tube control unit is controlled to maintain the same state, and the power supply unit control unit is controlled to maintain the same state. When the output of the second comparison unit is “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “L”, the fourth self-drive unit is The fluorescent tube control unit is controlled to maintain the state as it is, and the power supply control unit is controlled to immediately shut off (OFF) the power supply. In addition, if the output of the second comparison unit is “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”, the fourth self The drive unit controls the fluorescent tube unit control unit so as to maintain the state as it is, and controls the power source unit control unit so as to maintain the state as it is.

  In addition, when the output of the second comparison unit is “no output (normal)”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “H”, the fourth self-driving unit Controls the fluorescent tube control unit to maintain the state as it is, and controls the power source control unit to maintain the state as it is. Further, when the output of the second comparison unit is “no output (normal)”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “L”, the fourth self-drive unit Controls the fluorescent tube control unit so as to maintain the state as it is, and controls the power supply control unit so that the power supply is immediately shut off (OFF). Also, if the output of the second comparison unit is “No output (normal)”, the user control signal is “Normal / Dark”, and the output of the third comparison unit is “No output (Normal)”, The four self-driving units control the fluorescent tube unit control unit to maintain the state as it is, and control the power source unit control unit to maintain the state as it is.

  In addition, according to the configuration of this fluorescent tube system, it is possible to input not only the protection of the backlight but also a circuit involving load fluctuations such as voice changes and circuit conditions that change the load due to key operations (by user control) to the control unit. It is possible to eliminate fuses in all input stages of the product.

      <Simple explanation of effect of Embodiment 4>

  According to the fluorescent tube system of this embodiment, the voltage of the fluorescent tube and / or the power supply unit can be controlled based on the output results of the third comparison unit and the second comparison unit. It is possible to detect the voltage and return the fluorescent tube system to a normal state.

  << Embodiment 5 >>

<Concept of Embodiment 5>
The concept of this embodiment will be described below. The fluorescent tube system of the present embodiment monitors the voltage of the power supply unit, the tube voltage of the fluorescent tube unit, and the transient voltage, thereby detecting the detected voltage of the power supply unit, the tube voltage of the fluorescent tube unit, and the transient state. The fluorescent tube unit control unit and / or the power supply unit control unit is driven according to the voltage to protect the fluorescent tube unit or / and the power supply unit.

<Clarification of configuration requirements>
In the following, the configuration requirements of this embodiment will be clarified.
The fluorescent tube system of this embodiment includes a fluorescent tube unit, a power supply unit, a fluorescent tube unit control unit, a power supply unit control unit, a fluorescent tube unit voltage information acquisition unit, a first normal voltage information holding unit, One comparison unit, a power supply unit voltage information acquisition unit, a second normal voltage information holding unit, a second comparison unit, a fifth self-drive unit, a transient state voltage information acquisition unit, and a third normal voltage information holding unit And a third comparison section.

<Description of configuration requirements>
The configuration requirements of this embodiment will be described below.

(Fluorescent tube section), (Power supply section), (Fluorescent tube section control section), (Power supply section control section), (Fluorescent tube section voltage information acquisition section), (First normal voltage information holding section), (First comparison) Part), (transient state voltage information acquisition part), (third normal voltage information holding part), (third comparison part)
Fluorescent tube section, power supply section, fluorescent tube section control section, power supply section control section, fluorescent tube section voltage information acquisition section, first normal voltage information holding section, first comparison section, transient state voltage information acquisition section, third normal voltage Since the information holding unit and the third comparison unit are the same as those in the third embodiment, description thereof is omitted.

(Power supply voltage information acquisition unit), (Second normal voltage information holding unit), (Second comparison unit)
Since the power supply unit voltage information acquisition unit, the second normal voltage information holding unit, and the second comparison unit are the same as those in the fourth embodiment, description thereof will be omitted.

(Fifth self-driving part)
The fifth self-driving unit has the fluorescent tube control unit and / or the power supply control unit based on the comparison result in the third comparison unit, the comparison result in the second comparison unit, and the comparison result in the first comparison unit. To drive. Here, “based on the comparison result” means that the fluorescent tube controller or / and the power supply controller are driven according to the signals output from the third comparator, the second comparator, and the first comparator. It is. Here, “drive” means to drive the fluorescent tube control unit or / and the power supply control unit so that the fluorescent tube unit or / and the power supply unit have a predetermined voltage. “Predetermined voltage” refers to a voltage set when designing a fluorescent tube system.

  24, 25, 26, and 27 are tables showing an example of control of the fifth self-driving unit.

  FIG. 24 shows a case where the outputs of the first comparison unit and the second comparison unit are both “H”. For example, when both the outputs of the first comparison unit and the second comparison unit are “H”, the user control signal is “bright”, and the output of the third comparison unit is “H”, the fifth self-driving unit Controls the fluorescent tube control unit to change the duty in the low luminance direction, and controls the power supply control unit to shut off (that is, it does not reach the specified voltage within a certain period). If this happens, turn off the power). Further, when both the outputs of the first comparison unit and the second comparison unit are “H”, the user control signal is “bright”, and the output of the third comparison unit is “L”, the fifth self-drive unit Controls the fluorescent tube control unit to shut off (OFF), and controls the power supply control unit to immediately shut off (OFF) the power supply. In addition, when both the outputs of the first comparison unit and the second comparison unit are “H”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”, The five self-driving units control the fluorescent tube control unit to change the duty in the low luminance direction, and control the power supply control unit to maintain the power supply.

  In addition, when both the outputs of the first comparator and the second comparator are “H”, the user control signal is “normal / dark”, and the output of the third comparator is “H”, the fifth self The drive unit controls the fluorescent tube unit control unit to further change the duty in the low luminance direction, and controls the power source unit control unit in the blocking direction. In addition, when both the outputs of the first comparison unit and the second comparison unit are “H”, the user control signal is “normal / dark” signal, and the output of the third comparison unit is “L”, the fifth self The drive unit controls the fluorescent tube unit control unit to shut off (OFF), and controls the power source unit control unit to immediately shut off (OFF) power supply. Also, if both the output of the first comparator and the second comparator are “H”, the user control signal is “normal / dark”, and the output of the third comparator is “no output (normal)” The fifth self-drive unit controls the fluorescent tube unit control unit to change the duty in the low luminance direction, and controls the power source unit control unit to maintain power supply.

  FIG. 25 shows a case where the outputs of the first comparison unit and the second comparison unit are both “L”. For example, when both the outputs of the first comparison unit and the second comparison unit are “L”, the user control signal is “bright”, and the output of the third comparison unit is “H”, the fifth self-drive unit Controls the fluorescent tube control unit so as to maintain the state as it is, and controls the power supply control unit in a blocking direction. Further, when both the outputs of the first comparison unit and the second comparison unit are “L”, the user control signal is “bright”, and the output of the third comparison unit is “L”, the fifth self-drive unit Controls the fluorescent tube control unit to shut off (OFF), and controls the power supply control unit to immediately shut off (OFF) the power supply. Further, when both the outputs of the first comparison unit and the second comparison unit are “L”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”, The five self-driving units control the fluorescent tube unit control unit to change the duty in the low luminance direction, and control the power source unit control unit to shut off.

  If the outputs of the first comparator and the second comparator are both “L”, the user control signal is “normal / dark”, and the output of the third comparator is “H”, the fifth self The drive unit controls the fluorescent tube unit control unit so as to maintain the state as it is, and controls the power source unit control unit in a blocking direction. If the outputs of the first comparison unit and the second comparison unit are both “L”, the user control signal is “normal / dark”, and the output of the third comparison unit is “L”, the fourth self The drive unit controls the fluorescent tube unit control unit to shut off (OFF), and controls the power source unit control unit to immediately shut off (OFF) power supply. Also, if both the output of the first comparator and the second comparator are “L”, the user control signal is “normal / dark”, and the output of the third comparator is “no output (normal)” The fifth self-drive unit controls the fluorescent tube unit control unit to change the duty in the low luminance direction and controls the power source unit control unit in the shut-off direction.

  FIG. 26 shows a case where the outputs of the first comparison unit and the second comparison unit are both “no output (normal)”. For example, if both the outputs of the first and second comparison units are “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “H”, The five self-driving units control the fluorescent tube control unit so as to maintain the state as it is, and control the power supply unit control unit so as to maintain the state as it is. In addition, when both the outputs of the first comparison unit and the second comparison unit are “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “L”, The five self-driving units control the fluorescent tube control unit to maintain the state as it is, and control the power supply control unit to immediately shut off (OFF) the power supply. . In addition, both the output of the first comparison unit and the second comparison unit are “no output (normal)”, the user control signal is “bright”, and the output of the third comparison unit is “no output (normal)”. In this case, the fifth self-driving unit controls the fluorescent tube control unit to maintain the state as it is, and controls the power supply unit control unit to maintain the state as it is. .

  Also, if the outputs of both the first and second comparators are “no output (normal)”, the user control signal is “normal / dark”, and the output of the third comparator is “H” The fifth self-driving unit controls the fluorescent tube control unit to maintain the state as it is, and controls the power supply unit control unit to maintain the state as it is. Also, if the outputs of the first and second comparison units are both “no output (normal)”, the user control signal is “normal / dark”, and the output of the third comparison unit is “L” The fifth self-drive unit controls the fluorescent tube unit control unit so as to maintain the state as it is, and immediately shuts off (OFF) the power supply to the power unit control unit. Control. Also, the outputs of the first and second comparators are both “no output (normal)”, the user control signal is “normal / dark”, and the output of the third comparator is “no output (normal)”. In this case, the fifth self-driving unit controls the fluorescent tube unit control unit so as to maintain the same state, and the power source unit control unit maintains the state as it is. Control.

  FIG. 27 shows a case where the outputs of the first comparison unit and the second comparison unit do not match. In this case, as an example, it is determined that all are abnormal, and the fifth self-drive unit controls the fluorescent tube unit control unit to shut off (OFF), and the power source unit control unit Controls to immediately shut off (OFF) the power supply.

  In addition, according to the configuration of this fluorescent tube system, it is possible to input not only the protection of the backlight but also a circuit involving load fluctuations such as voice changes and circuit conditions that change the load due to key operations (by user control) to the control unit. It is possible to eliminate fuses in all input stages of the product.

(Fluorescent tube system)
The fluorescent tube system of this embodiment includes a fluorescent tube unit, a power supply unit, a fluorescent tube unit control unit, a power supply unit control unit, a fluorescent tube unit voltage information acquisition unit, a first normal voltage information holding unit, One comparison unit, a power supply unit voltage information acquisition unit, a second normal voltage information holding unit, a second comparison unit, a fifth self-drive unit, a transient state voltage information acquisition unit, and a third normal voltage information holding unit And a third comparison unit. The fluorescent tube system of the present embodiment monitors the voltage of the power supply unit, the tube voltage of the fluorescent tube unit, and the transient voltage, thereby detecting the detected voltage of the power supply unit, the tube voltage of the fluorescent tube unit, and the transient voltage. In response, the fluorescent tube control unit or / and the power supply control unit are driven to protect the fluorescent tube unit or / and the power supply unit.

      <Simple explanation of effect of embodiment 5>

  According to the fluorescent tube system of the present embodiment, the voltage of the fluorescent tube and / or the power supply unit can be controlled by the output results of the third comparison unit, the second comparison unit, and the first comparison unit. It is possible to detect an abnormal voltage in the fluorescent tube section and return the fluorescent tube system to a normal state.

  The present invention can be applied to a fluorescent tube system used for a liquid crystal display having a backlight.

Functional block diagram of Embodiment 1 Explanatory drawing of the voltage-current characteristic of the fluorescent tube part of Embodiment 1 The figure explaining control of the 1st self-drive part of Embodiment 1. Flow chart of processing of Embodiment 1 Functional block diagram of Example 1 of Embodiment 1 The figure explaining control of the 1st self-drive part of Example 1 of Embodiment 1 Functional block diagram of Embodiment 2 The figure explaining control of the 2nd self-drive part of Embodiment 2. Flow chart of processing of embodiment 2 Functional block diagram of Example 2 of Embodiment 2 The figure explaining control of the 2nd self-drive part of Example 2 of Embodiment 2 Functional block diagram of Embodiment 3 Process Flow of Embodiment 3 Functional block diagram of Example 3 of Embodiment 3 The figure explaining the control 1 of the 3rd self-drive part of Example 3 of Embodiment 3 The figure explaining the control 2 of the 3rd self-drive part of Example 3 of Embodiment 3 The figure explaining the control 3 of the 3rd self-drive part of Example 3 of Embodiment 3 Functional block diagram of Embodiment 4 Process Flow of Embodiment 4 Functional block diagram of Example 4 of Embodiment 4 The figure explaining the control 1 of the 4th self-drive part of Example 4 of Embodiment 4. The figure explaining the control 2 of the 4th self-drive part of Example 4 of Embodiment 4 The figure explaining control 3 of the 4th self-drive part of Example 4 of Embodiment 4 The figure explaining the control 1 of the 5th self-drive part of Embodiment 5. The figure explaining the control 2 of the 5th self-drive part of Embodiment 5. The figure explaining the control 3 of the 5th self-drive part of Embodiment 5. The figure explaining control 4 of the 5th self-drive part of Embodiment 5. The figure explaining the transient state voltage information of Embodiment 3.

Explanation of symbols

0100 Fluorescent tube system 0101 Fluorescent tube unit 0102 Power supply unit 0103 Fluorescent tube unit control unit 0104 Power supply unit control unit 0105 Fluorescent tube unit voltage information acquisition unit 0106 First normal voltage information holding unit 0107 First comparison unit 0108 First self-driving unit

Claims (9)

A fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit,
A fluorescent tube unit voltage information acquisition unit for acquiring fluorescent tube unit voltage information, which is information indicating the voltage of the fluorescent tube unit;
A first normal voltage information holding unit that holds first normal voltage information that is information on a voltage that the fluorescent tube unit should have in a normal state according to a control state of the fluorescent tube unit control unit;
A first comparison unit that compares the fluorescent tube voltage information acquired by the fluorescent tube voltage information acquisition unit with the first normal voltage information held by the first normal voltage information holding unit;
A first self-driving unit that drives the fluorescent tube control unit or / and the power source control unit based on the comparison result in the first comparison unit;
A fluorescent tube system.   2. The fluorescent tube system according to claim 1, wherein the first normal voltage information holding unit holds a plurality of pieces of first normal voltage information according to the control state.   3. The fluorescent tube system according to claim 2, wherein the first comparison unit includes selection comparison means that obtains specific first normal voltage information from a plurality of first normal voltage information according to the control state and performs comparison. A fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit,
A power supply unit voltage information acquisition unit for acquiring power supply unit voltage information which is information indicating the voltage of the power supply unit;
A second normal voltage information holding unit that holds second normal voltage information that is information on a voltage that the power supply unit should have in a normal state according to a control state of the power supply unit control unit;
A second comparison unit that compares the power supply unit voltage information acquired by the power supply unit voltage information acquisition unit with the second normal voltage information held by the second normal voltage information holding unit;
A second self-driving unit that drives the fluorescent tube control unit or / and the power supply control unit based on the comparison result in the second comparison unit;
A fluorescent tube system.   5. The fluorescent tube system according to claim 4, wherein the second normal voltage information holding unit holds a plurality of second normal voltage information corresponding to the control state.   6. The fluorescent tube system according to claim 5, wherein the second comparison unit includes selection comparison means that obtains specific second normal voltage information from a plurality of second normal voltage information according to the control state and performs comparison. A fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit,
A fluorescent tube unit voltage information acquisition unit for acquiring fluorescent tube unit voltage information, which is information indicating the voltage of the fluorescent tube unit;
A first normal voltage information holding unit that holds first normal voltage information that is information on a voltage that the fluorescent tube unit should have in a normal state according to a control state of the fluorescent tube unit control unit;
A first comparison unit that compares the fluorescent tube voltage information acquired by the fluorescent tube voltage information acquisition unit with the first normal voltage information held by the first normal voltage information holding unit;
A transient state voltage information acquisition unit for acquiring transient state voltage information, which is information indicating a transient state voltage of the fluorescent tube unit;
A third normal voltage information holding unit for holding third normal voltage information that is information indicating a voltage in a transient state that the fluorescent tube unit should have in a normal state;
A third comparison unit that compares the transient state voltage information acquired by the transient state voltage information acquisition unit with the third normal voltage information held by the third normal voltage information holding unit;
A third self-driving unit that drives the fluorescent tube control unit or / and the power source control unit based on the comparison result in the third comparison unit and the comparison result in the first comparison unit;
A fluorescent tube system. A fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit,
A power supply unit voltage information acquisition unit for acquiring power supply unit voltage information which is information indicating the voltage of the power supply unit;
A second normal voltage information holding unit that holds second normal voltage information that is information on a voltage that the power supply unit should have in a normal state according to a control state of the power supply unit control unit;
A second comparison unit that compares the power supply unit voltage information acquired by the power supply unit voltage information acquisition unit with the second normal voltage information held by the second normal voltage information holding unit;
A transient state voltage information acquisition unit for acquiring transient state voltage information, which is information indicating a transient state voltage of the fluorescent tube unit;
A third normal voltage information holding unit for holding third normal voltage information that is information indicating a voltage in a transient state that the fluorescent tube unit should have in a normal state;
A third comparison unit that compares the transient state voltage information acquired by the transient state voltage information acquisition unit with the third normal voltage information held by the third normal voltage information holding unit;
A fourth self-driving unit that drives the fluorescent tube unit control unit and / or the power supply unit control unit based on the comparison result in the third comparison unit and the comparison result in the second comparison unit;
A fluorescent tube system. A fluorescent tube system having a fluorescent tube unit, a power supply unit that supplies power to the fluorescent tube unit, a fluorescent tube unit control unit, and a power supply unit control unit,
A fluorescent tube unit voltage information acquisition unit for acquiring fluorescent tube unit voltage information, which is information indicating the voltage of the fluorescent tube unit;
A first normal voltage information holding unit that holds first normal voltage information that is information on a voltage that the fluorescent tube unit should have in a normal state according to a control state of the fluorescent tube unit control unit;
A first comparison unit that compares the fluorescent tube voltage information acquired by the fluorescent tube voltage information acquisition unit with the first normal voltage information held by the first normal voltage information holding unit;
A power supply unit voltage information acquisition unit for acquiring power supply unit voltage information which is information indicating the voltage of the power supply unit;
A second normal voltage information holding unit that holds second normal voltage information that is information on a voltage that the power supply unit should have in a normal state according to a control state of the power supply unit control unit;
A second comparison unit that compares the power supply unit voltage information acquired by the power supply unit voltage information acquisition unit with the second normal voltage information held by the second normal voltage information holding unit;
A transient state voltage information acquisition unit for acquiring transient state voltage information, which is information indicating a transient state voltage of the fluorescent tube unit;
A third normal voltage information holding unit for holding third normal voltage information that is information indicating a voltage in a transient state that the fluorescent tube unit should have in a normal state;
A third comparison unit that compares the transient state voltage information acquired by the transient state voltage information acquisition unit with the third normal voltage information held by the third normal voltage information holding unit;
The fluorescent tube control unit or / and the power supply control unit are driven based on the comparison result in the third comparison unit, the comparison result in the second comparison unit, and the comparison result in the first comparison unit. A fifth self-driving unit;
A fluorescent tube system.

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