JP2006103566A - Display device and vehicular display system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of preventing instantaneous blinking of a light emitting element without increasing the number of components. <P>SOLUTION: The display device 20 comprises a plurality of power supply lines 20L which are electrically connected to an external equipment to detect the predetermined state change corresponding to an object for display to supply the power to the external equipment from a power supply 25 according to the detection of the state change of the external equipment 10, and a light emitting device 21 assembled in the power supply lines 20L so as to be lit by the power supply, displays the state change of the object to be displayed by the lighting of the light emitting element 21, and further comprises a light extinction period detection means 26a to detect the start of the predetermined light extinction period to maintain the light extinction period of the light emitting element 21, and a power supply interrupting means 27 to interrupt the power supply to the power supply lines 20L from the power supply 25 according to the detection of the light extinction period detection means 26a for the light extinction period. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device and a vehicle display system, and more particularly to a display device and a vehicle display system in which lighting and extinguishing of a light-emitting element incorporated therein is controlled by an electrically connected external device. .

  The vehicle is equipped with multiple detection devices that have the function of judging water temperature abnormality, brake lamp abnormality, etc., and these detection devices are connected to a display device that displays vehicle status such as vehicle speed and engine speed. Has been. The display device corresponds to the detection device and includes a light source that is controlled to be turned on and off according to an output signal output from the detection device.

  If the light source is a light-emitting diode, if an abnormal voltage or current occurs in the electrical circuit in which the light-emitting diode is mounted, there will be a problem of a flashing light that causes the light-emitting diode to light at normal brightness for a short time. Problems such as deterioration of the appearance of the device and an uncomfortable feeling to the driver have occurred. As a countermeasure, it has been known that a light emitting diode and a capacitor are connected in parallel on a printed circuit board and mounted to prevent a flashing light by the capacitor.

  FIG. 4 is a block diagram showing a schematic configuration of a conventional vehicle display system. In FIG. 4, the vehicle display system is mounted on a vehicle and detects a plurality of external devices 10A that detect a change in state of a predetermined display target. , B and a display device 20 to which these are connected.

  The external devices 10A and B have control units 11A and 11B in which a well-known CPU or the like is used, and the input of the control units 11A and 11B is an ignition switch (IGN switch) of the vehicle via the input ports 12A and B. ) 30 is connected. The bases of the transistors 13A and 13B are connected to the outputs of the control units 11A and 11B. The emitters of the transistors 13A and 13B are grounded, and the collectors are connected to one of the capacitors 14A and 14B and the output ports 15A and 15B. The capacitors 14A and 14B are for noise countermeasures, and the other is grounded.

  The display device 20 is electrically connected to the external devices 10A and 10B, and a plurality of power supply lines 20LA that supply power from the power source 25 to the external devices 10A and 10B in response to detection of a change in the state of the external devices 10A and 10B. Has LB. The power supply lines 20LA, LB are connected to input ports 24A, B corresponding to the external devices 10A, B. The power supply lines 20LA and LB correspond to the external devices 10A and 10B, and light-emitting diodes 21A and 21B that are turned on and off according to the state, and capacitors connected in parallel to the light-emitting diodes 21A and 21B. 22A and B are incorporated.

  One of the anodes of the light emitting diodes 21A and 21B and the capacitors 22A and 22B is connected to the power supply 25 supplied in response to the IGN switch 30 being turned on, and the cathode and the other are connected to one of the resistors 23A and B. Yes. The other of the resistors 22A and B is connected to the input ports 24A and B.

  By connecting the input ports 24A, B of the display device 20 and the output ports of the external devices 10A, B via a cable, the external devices 10A, B and the display device 20 are electrically connected. Then, the transistors 13A and 13B are turned on by the control units 11A and 11B in the external devices 10A and 10B, whereby a current flows from the power supply 25 to the external devices 10A and 10B via the output ports 24A and 24B in the display device 20. By flowing, the light emitting diodes 21A and 21B incorporated in the power supply lines 20LA and LB emit light.

  In the vehicle display system, when a predetermined operation (for example, full lighting of the indicator) associated with the IGN switch 30 is performed, a rush current (inrush current) flows through the capacitors 14A and 14B of the external devices 10A and B. Since the surge current generated in the display device 20 is consumed for charging the capacitors 22A and 22B, it prevents the current from flowing through the light emitting diodes 21A and 21B and turning on for a moment.

Furthermore, in an LED display device equipped with an LED (light emitting diode), a technical idea for reducing spike noise generated when the LED is turned on and off is disclosed. This LED display device is provided with a plurality of capacitors for suppressing the noise voltage that increases almost uniformly toward the terminal side of the conduction path in the conduction path from the power connector to the LED provided on the circuit board. A technical idea for reducing spike noise generated in a power supply line during on and off is disclosed (see Patent Document 1).
JP 2001-83939 A

  However, when there are many external devices connected to the display device described above, the number of diodes (light emitting elements) increases according to the number of external devices, so in the display device, the diodes are connected in parallel. As a result, the number of capacitors to be mounted has increased, and there has been a problem that a large mounting space is required for a substrate on which these capacitors are mounted. In recent years, the number of external devices connected with the increase in the functions of the display device has increased, and there has been a problem that the cost of the display device increases with an increase in the number of components.

  Therefore, in view of the above-described problems, an object of the present invention is to provide a display device that prevents a flashing of a light emitting element without increasing the number of components.

  In order to solve the above problems, the display device according to the first aspect of the present invention is provided in an external device 10 that detects a change in state predetermined for a display object, as shown in the basic configuration diagram of FIG. A plurality of power supply lines 20L that are electrically connected to supply power to the external device 10 from a power supply 25 in response to detection of a change in the state of the external device 10, and the power supply that is lit by the supply of the power A light-emitting element 21 incorporated in the line 20 </ b> L, and a predetermined turn-off period in which the light-emitting element 21 is turned off in the display device 20 that displays a change in state of the display target by turning on the light-emitting element 21. The light extinction period detecting means 26a for detecting the start of the power supply, and the power supply line 20L from the power supply 25 in accordance with the detection of the light extinction period detecting means 26a A power supply interrupting means 27 for interrupting the supply across the turn-off period, characterized in that it comprises a.

  According to the display device of the present invention described in claim 1, when a change in state corresponding to a display target is detected by the external device 10, the power supply line 20L electrically connected to the external device 10 is Power is supplied to the external device 10 from 25, and the light emitting element 21 emits light by supplying this power. Further, when the start of the extinguishing period is detected by the extinguishing period detection means 26a, the supply of power from the power supply 25 to the power supply line 20L is interrupted by the power supply interruption means 27 during this extinction period.

  In order to solve the above problem, the invention according to claim 2 is the display device according to claim 1, as shown in the basic configuration diagram of FIG. 1, wherein the extinguishing period detecting means 26 a is the display device 20. A change from an off state to an on state of an ignition switch of a vehicle on which is mounted is detected as the start of the extinguishing period.

  According to the display device of the present invention described in claim 2 above, when the change of the ignition switch of the vehicle from the OFF state to the ON state is detected by the extinguishing period detection means 26a as the start of the extinguishing period, the ignition switch is turned on. The power supply from the power supply 25 to the power supply line 20L is cut off for a predetermined time set as the turn-off period.

  The vehicle display system according to claim 3, which is made according to the present invention in order to solve the above-described problem, is a vehicle display that displays a plurality of types of state changes in a vehicle to be displayed, as shown in the basic configuration diagram of FIG. 1. 3. The display device according to claim 1, wherein in the system, a plurality of external devices 10 that detect the change in state corresponding to the display target are electrically connected to the plurality of external devices 10. The display device 20 is characterized in that the light emitting element 21 is not turned on even if the external device 10 detects a change in state during the extinguishing period.

  According to the vehicle display system of the present invention described in claim 3, when a change in state in the vehicle to be displayed is detected by the external device 10, the power supply line electrically connected to the external device 10 20L supplies power from the power source 25 to the external device 10, and the light emitting element 21 emits light by the supply of this power. In addition, when the start of the extinguishing period is detected by the extinguishing period detection unit 26a, the supply of power from the power supply 25 to the power supply line 20L is interrupted by the power supply cutoff unit 27 during the extinguishing period, and the light emitting element 21 The off state is maintained.

  As described above, according to the display device of the present invention described in claim 1, in the configuration in which the light emitting element is turned on by the control of the external device, the light extinguishing period for maintaining the light emitting element is turned off in advance. Since the power supply to the light emitting element is cut off during the period, the display element can be shortened by setting the period during which abnormal voltage and current are generated in the electric circuit where the light emitting element is mounted as the extinguishing period. It is possible to prevent the occurrence of a flashing light that is normally lit. Further, since it is not necessary to connect a capacitor for preventing flashing in parallel to the light emitting element, it is possible to solve the problem of requiring a large board mounting space as the number of light emitting elements increases. Therefore, it is possible to provide a display device that can prevent a flashing of a light emitting element without increasing the number of components.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the change from the off state to the on state of the ignition switch of the vehicle is the start of the extinguishing period, and the light emitting element is emitted during the extinguishing period Since the power is not supplied from the power supply line even if the external device confirms the operation such as the initial operation according to the ignition switch being turned on, the vehicle's ignition switch is turned on. It is possible to prevent the flashing of the light emitting element.

  As described above, according to the vehicle display system of the present invention described in claim 3, during the predetermined extinction period, the supply of power to the power supply line is interrupted and the vehicle to be displayed by the external device. Since the light emitting element is kept off even when a change in state is detected, the period in which abnormal voltage and abnormal current occur in the electric circuit where the light emitting element is mounted is set as the extinguishing period. It is possible to prevent the occurrence of a flashing lamp in which the element is lit at normal brightness for a short time. Further, since it is not necessary to connect a capacitor for preventing flashing in parallel to the light emitting element, it is possible to solve the problem of requiring a large board mounting space as the number of light emitting elements increases. Therefore, it is possible to prevent the driver from feeling uncomfortable with the flashlight with a simple configuration.

  Hereinafter, an embodiment of a display system for a vehicle having a display device according to the present invention will be described with reference to the drawings of FIGS. In addition, the same code | symbol is attached | subjected to the part which is the same as that of what was demonstrated in the prior art, or the detailed description is abbreviate | omitted.

  FIG. 2 is a block diagram showing a schematic configuration of a display system for a vehicle having a display device according to the present invention. In FIG. 2, the display system for a vehicle is mounted on a vehicle as described above and is a predetermined display object. A plurality of external devices 10A and 10B that detect a change in the state and a display device 20 to which these devices are connected are configured. As described above, the external devices 10A and 10B include the control units 11A and 11B, the transistors 13A and 13B, and the capacitors 14A and 14B.

  The display device 20 is electrically connected to the external devices 10A and 10B, and a plurality of power supply lines 20LA that supply power from the power source 25 to the external devices 10A and 10B in response to detection of a change in the state of the external devices 10A and 10B. LB, LC... In order to simplify the description, only the power supply lines 20LA and LB will be described below.

  One of these power supply lines 20LA, LB is connected to the input ports 24A, B corresponding to the external devices 10A, B. The power supply lines 20LA and LB incorporate light emitting diodes 21A and 21B corresponding to the external devices 10A and 10B, which are turned on and off according to the state.

  The display device 20 further includes a microprocessor (MPU) 26 that operates according to a predetermined program. As is well known, the MPU 26 includes a central processing unit (CPU) 26a that performs various processes and controls according to a predetermined program, a ROM 26b that is a read-only memory storing a program for the CPU 26a, and various data. And a RAM 26c, which is a readable / writable memory having an area necessary for processing operations of the CPU 26a.

  An ignition switch 30 of the vehicle is connected to the MPU 26 so that a change in state from an off state to an on state can be detected. The ignition switch 30 is similarly connected to the control units 11A and 11B of the external devices 10A and 10B.

  The ROM 26b stores various programs such as a program for causing the CPU 26a to function as an extinguishing period detection unit that detects the start of a predetermined extinguishing period that maintains the extinguishing state of the light emitting diodes 21 (light emitting elements) A and B. ing. The CPU 26a executes these programs to perform various display controls and detect the start of the extinguishing period.

  In the best mode, a change from the off state to the on state of the ignition switch 30 of the vehicle on which the display device 20 is mounted is detected as the start of the extinguishing period. The extinguishing period corresponds to a period in which an abnormal voltage and an abnormal current occur in the electric circuit in which the light emitting diodes 21A and B are mounted. By setting this period as the extinguishing period, the display element can be shortened. It is intended to prevent the occurrence of a flashing light that is normally lit.

  The display device 20 further includes a transistor 27 corresponding to a power supply cut-off means for cutting off the supply of power from the power supply 25 to the power supply lines 20LA and LB over the light-off period in response to detection of the start of the light-off period by the MPU 26. It is composed. The base of the transistor 27 is connected to the output of the MPU 26, the emitter is connected to the power source 25, and the collector is connected to the other of the power supply lines 20LA and LB.

  When the transistor 27 is turned on in response to an output signal from the MPU 26, the power supply 25 can supply power to the power supply lines 20LA and LB. Moreover, when it changes to an OFF state according to the output signal from MPU26, it will be in the state which interrupted | blocked supply of the electric power from the power supply 25 to power supply line 20LA, LB.

  In the best mode, the case where the transistor 27 is a PNP type will be described. However, the present invention is not limited to this, and an NPN type transistor or FET may be used. The number of transistors 27 is provided in accordance with the amount of heat, but in the best mode, one case will be described.

  FIG. 3 is a flowchart showing an example of a processing outline according to the present invention executed by the CPU of FIG. In FIG. 3, the CPU 26a operating in the power saving mode determines whether or not the ignition switch 30 has changed from the off state to the on state in step S1 (light extinction period detecting means). If it is determined that the ignition switch 30 has not been turned on (N in S1), the semi-Aichi process is repeated to wait for the ignition switch 30 to be turned on. On the other hand, when it determines with having changed to ON, it progresses to step S2.

  In step S2, an output signal for turning off the transistor 27 is output to the transistor 27, and a predetermined time corresponding to the extinguishing period is designated as a certain time for a timer that times out when a certain time elapses, and a start is requested. Then, the process proceeds to step S4.

  In step S4, it is determined whether or not a predetermined time has elapsed based on the timeout of the timer. If it is determined that a time-out has not occurred, that is, a certain time has not elapsed (N in S4), this determination process is repeated to wait for a certain time to elapse. On the other hand, if it is determined that a time-out has occurred, that is, a certain time has elapsed (Y in S4), the process proceeds to step S5.

  In step 5, an output signal that requests the transistor 27 to be turned on is output to the transistor 27, whereby the transistor 27 is turned on, and power supply from the power supply 25 to the power supply lines 20LA and LB is performed. It becomes possible.

  Next, an example of the operation (action) according to the present invention of the vehicle display system 1 in the configuration described above will be described below.

  When the ignition switch 30 of the vehicle changes from the off state to the on state and the display device 20 detects the change, the display device 20 determines that the extinguishing period has started, changes the transistor 27 to the off state, and supplies power from the power source 25. The power supply to the lines 20LA and LB is cut off. In addition, when the external devices 10A and B detect the change of the ignition switch 30 to the on state, the on / off switching operation of the transistors 13A and 13B is instantaneously confirmed by the operation confirmation. However, since the power supply from the power source 25 to the electrically connected power supply line 20L is interrupted, the light emitting diodes 21A and 21B can be prevented from instantaneously emitting light by the confirmation operation.

  Further, the display device 20 changes the transistor 27 to the ON state after detecting the start of the extinguishing period, and changes the transistor 27 to the ON state, and the external devices 10A, B from the power supply 25 via the power supply lines 20LA, LB. It becomes possible to supply power to the. In this state, when the external device 10A detects a state change corresponding to the display target and the transistor 13A is turned on, the power supply line 20LA supplies power from the power supply 25 to the external device 10A. Thus, the light emitting diode 21A emits light.

  As described above, according to the display device 20 of the present invention, in the configuration in which the light emitting diodes (light emitting elements) 21A and B are turned on by the control of the external devices 10A and B, the light emitting diodes 21A and 21B are maintained in the unlit state. Since the turn-off period to be performed is determined in advance and the power supply to the light-emitting diodes 21A and 21B is cut off during the turn-off period, abnormal voltage and current are generated in the electric circuit in which the light-emitting diodes 21A and B are mounted. By setting the period as the extinguishing period, it is possible to prevent the occurrence of a flashing lamp in which the light emitting diodes 21A and 21B are lit at a normal luminance for a short time. In addition, since it is not necessary to connect a capacitor for preventing flashing in parallel to the light emitting diodes 21A and 21B, the problem of requiring more mounting space on the board as the number of light emitting diodes 21A and 21B increases is solved. can do.

  Therefore, it is possible to provide the display device 20 that can prevent the flashing of the light emitting diodes 21A and 21B without increasing the number of components. And according to the vehicle display system 1, it is possible to prevent the driver from feeling uncomfortable with the flashlight with a simple configuration.

It is a lineblock diagram showing the basic composition of the display system for vehicles which has the display concerning the present invention. It is a lineblock diagram showing a schematic structure of a display system for vehicles which has a display concerning the present invention. It is a flowchart which shows an example of the process outline | summary which concerns on this invention which CPU of FIG. 2 performs. It is a block diagram which shows schematic structure of the conventional vehicle display system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display system for vehicles 10 External apparatus 20 Display apparatus 20L Power supply line 21 Light emitting element (light emitting diode)
25 Power source 26a Light extinction period detection means (CPU of display device)
27 Power supply cutoff means (transistor of display device)

Claims (3)

A plurality of power supply lines that are electrically connected to an external device that detects a predetermined state change corresponding to a display target and supplies power from the power source to the external device in response to detection of the state change of the external device And a light-emitting element incorporated in the power supply line so as to be lit by the supply of power, and a display device that displays a change in state of the display object by lighting the light-emitting element,
A light extinction period detecting means for detecting the start of a predetermined extinction period for maintaining the light extinction state of the light emitting element;
Power supply cutoff means for cutting off the supply of power from the power source to the power supply line over the extinction period in response to detection of the extinguishing period detection means;
A display device comprising: The display device according to claim 1, wherein the extinguishing period detection unit detects a change from an off state to an on state of an ignition switch of a vehicle on which the display device is mounted as the start of the extinguishing period. In a vehicle display system that displays a plurality of types of state changes in a vehicle to be displayed,
A plurality of external devices that detect the state change predetermined corresponding to the display target, and the display device according to claim 1 or 2, wherein the plurality of external devices are electrically connected.
The display device for a vehicle, wherein the light emitting element is not turned on even if the external device detects a change in state during the turn-off period.

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