JP2005084031A - Vehicle instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase reaction speed of a display element furthermore than hitherto, and to reduce LCD drivers connected between an LCD element and an output terminal of a microcomputer relative to a vehicle instrument for digitally displaying hitherto vehicle speed or the total mileage by an LCD without installing additionally an output terminal for controlling the LCD on the microcomputer, in a vehicle instrument having a constitution digitally displaying the vehicle speed. <P>SOLUTION: The total mileage of the vehicle is digitally displayed by using the LCD. An LED 2 arranged in a segment pattern is used. A constitution is adopted, wherein the LCD element 1 is connected to a control output terminal 21 for controlling the LCD between control output terminals carried by the microcomputer 4, and the LED 2 is connected to the other control output terminal 22 not for LCD control between control output terminals carried by the microcomputer 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle instrument.

  FIG. 3 shows a schematic diagram of an electric circuit configuration of a conventional vehicle instrument. Conventionally, as shown in FIG. 3, a vehicle instrument generally used generally displays a vehicle speed in an analog manner by rotating a pointer 6 on a dial 5, and an LCD (Liquid Crystal Display) 3 displays odd and trip ( Some display (digital display) the vehicle's total travel distance and section travel distance).

  This vehicle meter is equipped with a control terminal 21 for controlling the LCD unit among the control output terminals of a microcomputer (hereinafter referred to as a microcomputer) 4 as a control unit, and an LCD unit as an odd and trip display unit. 3 is connected, and the movement inner terminal 22 is connected to a rotation inner unit for driving the pointer 6 to rotate.

  Conventionally, there are other vehicular instruments that digitally display not only odds and trips but also vehicle speeds with an LCD. A schematic diagram of the electric circuit configuration of this vehicle instrument is shown in FIG. In this vehicle instrument, as shown in FIG. 4, the LCD unit 3 is connected to a control terminal 21 for controlling the LCD among the control output terminals of the microcomputer 4 via the LCD driver 7. It has become.

  Here, the reason why the LCD driver 7 is used will be described. There are a static driving method and a dynamic driving method as LCD driving methods. Furthermore, there are dynamic drive systems having a DUTY ratio of 1/4 or 1/2, for example. The dynamic drive method has an advantage that the LCD can be driven with fewer terminals than the static drive method, but has a disadvantage that the response speed of the LCD is slow (particularly at low temperatures). For this reason, the speedometer can only employ up to 1/2 DUTY of the static drive system or the dynamic drive system. When the 1/2 DUTY of the static drive system or the dynamic drive system is adopted, many control wirings are required.

  On the other hand, the microcomputer 4 does not have a large number of control output terminals 21 for controlling the LCD, and if the LCD is directly connected to the control output terminal 21, the control output terminal 21 is insufficient. There is.

  For this reason, when such a microcomputer 4 is used, an LCD driver 7 is added between the microcomputer 4 and the LCD device 3 to solve the shortage of control output terminals.

  For display means for digitally displaying the vehicle speed, it is generally required that the reaction speed of the display element in the display means is high.

  Further, when the vehicle speed is digitally displayed by the LCD device 3, as shown in FIG. 4, since it is necessary to add the LCD driver 7, the cost for the vehicle instrument is high.

  As a method of connecting the LCD device 3 to the control output terminal of the microcomputer 4 without using the LCD driver 7, first, as a drive method of the LCD, a drive method (dynamic that can reduce the necessary control output terminals). A method of adopting a 1/4 DUTY of the driving method is conceivable, but as described above, it is not preferable from the viewpoint of reactivity.

  Secondly, a method of increasing the number of control output terminals of the microcomputer itself is conceivable. However, in this case as well, it is necessary to newly design and manufacture a microcomputer having such a configuration, which is not preferable. .

  In view of the above-mentioned points, it is a first object of the present invention to provide a vehicle instrument that digitally displays a vehicle speed and has a display element that has a faster response speed than conventional ones.

  In addition to the first object, a second object is to provide a vehicle instrument configured to digitally display the vehicle speed without using an LCD driver.

  In order to achieve the above object, the invention according to claim 1 uses the liquid crystal display element (3) as the travel distance display means and the light emitting diode (2) arranged in the segment pattern as the vehicle speed display means. It is a feature.

  As described above, in the digital instrument, by using the light emitting diode as the vehicle speed display means, the response at the low temperature can be made faster than the case of using the liquid crystal display.

  In the invention according to claim 2, the liquid crystal display (3) is used as a liquid crystal control output terminal (21) for controlling the liquid crystal display among the control output terminals (21, 22) of the control means. The vehicle speed display means uses a light emitting diode (2) arranged in a segment pattern, and this light emitting diode (2) is connected to the control output terminals (21, 22) of the control means. Among these, it is characterized in that it is connected to the control output terminal (22) excluding the liquid crystal control output terminal.

  Since the first control output terminal is insufficient, the liquid crystal display used for the mileage display means can be directly connected to the first control output terminal, but the liquid crystal display used for the vehicle speed display means is connected to the first control output. Even when it cannot be directly connected to the terminal, the control means may have a second control output terminal different from the first control terminal.

  In such a case, as in the present invention, a light emitting diode is used as the vehicle speed display means, and this light emitting diode is connected to the second control output terminal in the control means, so that the vehicle speed can be digitally adjusted without using an LCD driver. Can be displayed. As a result, the cost for the LCD driver can be reduced.

  The invention described in claim 2 has the same effect as that of the invention described in claim 1.

  Specifically, as shown in claim 3, the vehicle speed display means is configured to be irradiated with light from the light emitting diode (2) from the back side of the lens sheet (11) made of a translucent material. As the lens sheet (11), it is possible to use a lens sheet (11) on which a non-translucent substance is printed in the region (13) excluding the portion (12) corresponding to the light emitting diode.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

  1 (a) and 1 (b) show a vehicle meter according to an embodiment of the present invention, and FIG. 2 shows an electric circuit configuration of the meter. The main difference between the meter of this embodiment and the meter shown in FIG. 4 is that the vehicle speed is digitally displayed using LEDs.

  This instrument is used for automobiles and other vehicles, and is installed, for example, on an instrument panel of a passenger car. As shown in FIGS. 1 (a) and 2, the meter includes a display 1 having an LED (light emitting diode) display unit 1a and a liquid crystal display unit 1b, and a microcomputer 4 as control means.

  The LED display unit 1a digitally displays the vehicle speed. Although not shown, the LED display unit 1a includes LED elements arranged in a segment pattern and a lens sheet, and is configured to be irradiated with light from the back side of the lens sheet.

  More specifically, although not shown, the LED is mounted and soldered on a land pattern formed on a PCB (printed circuit board) substrate. Further, for example, LEDs are arranged in a figure of 8 so that numbers of 0 to 9 are represented by 7 segments per digit. Further, an LED for a vehicle speed unit “km / h” is also arranged separately. This may also be used as a liquid crystal backlight.

  On the other hand, as shown in FIG. 1B, the lens sheet 11 is made of a translucent material, for example, a transparent resin, and has a non-translucent substance in a region 13 excluding the portion 12 corresponding to the LED. Black printing is applied. Thereby, the part 12 corresponding to LED becomes a translucent area | region, and becomes the shape of a segment. Further, the portion 12 corresponding to the LED is black-printed with a translucent substance. Further, as shown in FIG. 1A, a vehicle speed unit pattern “km / h” is also formed on the lens sheet 11 by printing.

  The liquid crystal display unit 1b includes a general liquid crystal panel and a backlight illumination device. In the liquid crystal display unit 1b, odd and trip are switched and digitally displayed, and the remaining amount of fuel and the shift position are displayed.

  As shown in FIG. 2, the microcomputer 4 has a first control output terminal 21 for controlling the LCD and a second control output terminal 22 for controlling other than the LCD. Here, the first control output terminal 21 is an output terminal capable of switching the LCD display by applying a voltage to the LCD device. On the other hand, the second control output terminal 22 is an output terminal to which a voltage for driving the LCD cannot be applied among several control output terminals of the microcomputer 4.

  For example, if the microcomputer 4 has a movement output terminal for driving the hands as shown in FIG. 3, the movement output terminal becomes the second control output terminal 22. Note that the second control output terminal 22 is not limited to the movement output terminal, and any output terminal to which a voltage for driving the LCD as described above cannot be applied can be the second control output terminal 22.

  The liquid crystal display 3 of the liquid crystal display unit 1b is directly connected to the first control output terminal 21 without an LCD driver, and the LED 2 of the LED display unit 1a is connected to the second control output terminal 22. Is connected. For example, when the LED 2 is connected to the movement output terminal, the output terminal can pass a sufficient current to drive the LED, and therefore the LED 2 is connected to the output terminal via a resistor. In addition, when the LED is directly connected to another control output terminal instead of the first control output terminal 21 or the movement output terminal, the LED is connected to the control output terminal that has a small amount of current and cannot drive the LED. In the case of connecting the LEDs, the LEDs are connected through a transistor circuit.

  Although not shown, the microcomputer 4 is operated by being supplied with power from the battery when the ignition switch of the vehicle is turned on, for example. Further, as shown in FIG. 2, a vehicle speed sensor 31, a fuel sensor 32, and a shift position switch 33 are connected to the input terminals of the microcomputer 4.

In the vehicle instrument configured as described above, the microcomputer 4 controls the LED 2 in accordance with the electrical signal from the vehicle speed sensor 31, and the vehicle speed is digitally displayed on the LED display unit 1a. The microcomputer 4 receives the electrical signal from the vehicle speed sensor 31 and calculates the travel distance. The microcomputer 4 controls the LCD 3 to digitally display odd or trip on the liquid crystal display unit 1b.
Similarly, in the liquid crystal display unit 1b, when the microcomputer 4 receives the electric signals from the fuel sensor 32 and the shift position switch 33 and controls the LCD, the remaining fuel amount and the shift position are displayed.

  As described above, in the vehicle meter of the present embodiment, the vehicle speed is displayed digitally using the LED 2 and the vehicle speed is digitally displayed, and the LCD 3 is used as the odd and trip display means so that the odd and trip are digitally displayed. It has become. Since the response speed of the LED is faster than that of the LCD, the vehicle instrument of the present embodiment has a faster response speed than the case where a liquid crystal display is used as the vehicle speed display means. The response speed of is faster.

  Conventionally, as shown in FIG. 4, there is a vehicle meter in which an LCD is connected to a control output terminal of a microcomputer via an LCD driver. This is because, as described above, when LCDs are used as means for displaying odds, trips, etc. and vehicle speed display means, not all LCDs can be directly connected to the control output terminals.

  Therefore, in this embodiment, paying attention to other control output terminals except for the first control output terminal 21 of the microcomputer 4, an LED is used as the vehicle speed display means, and this LED is used as the second output of the microcomputer 4. To the control output terminal 22.

  As a result, the first control output terminal 21, which is limited in number, can be directly connected to the LCD element for displaying odds, trips, etc., without going through the LCD driver. As a result, the cost for the LCD driver can be reduced.

  In the present embodiment, the case where the trip display, the fuel remaining amount display, and the shift position are displayed using the LCD 3 has been described. However, the display device is not limited to the LCD element, and other display means such as an LED may be used. . Therefore, the number of LCD elements that can be used is determined by the number of first control output terminals 21 that the microcomputer 4 has, and accordingly, trip display, fuel remaining amount display, and shift position display means are provided. Change it.

  In the present embodiment, the case where seven segments per digit are used as the segment pattern of the LED 2 has been described. However, the number of segments is not limited to seven and may be other numbers.

(A) is a front view of the instrument for vehicles to which this invention is applied, (b) is the elements on larger scale of the LED display part 1a in (a). It is the schematic which shows the electric circuit structure of the meter for vehicles of FIG. It is the schematic which shows the electric circuit structure of the meter for vehicles in the conventional 1st example. It is the schematic which shows the electric circuit structure of the meter for vehicles in the conventional 2nd example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Display device, 1a ... LED display part, 1b ... Liquid crystal display part,
2 ... LED, 3 ... Liquid crystal display, 4 ... Microcomputer,
5 ... Dial, 6 ... Hand, 7 ... LCD driver 21 ... First control output terminal, 22 ... Second control output terminal,
31 ... Vehicle speed sensor, 32 ... Fuel sensor, 33 ... Shift position switch.

Claims (3)

Vehicle speed display means for digitally displaying the vehicle speed;
In a vehicular meter provided with travel distance display means for digitally displaying the total travel distance of the vehicle,
A vehicle instrument using a liquid crystal display (3) as the travel distance display means and a light emitting diode (2) arranged in a segment pattern as the vehicle speed display means. Vehicle speed display means for digitally displaying the vehicle speed;
Mileage display means for digitally displaying the total mileage of the vehicle using the liquid crystal display (3);
In a vehicular instrument comprising a control means (4) for controlling the vehicle speed display means and the travel distance display means,
The liquid crystal display (3) is connected to a liquid crystal control output terminal (21) for controlling the liquid crystal display among the control output terminals (21, 22) of the control means,
The vehicle speed display means uses a light emitting diode (2) arranged in a segment pattern, and the light emitting diode (2) is the control output terminal (21, 22) of the control means. A vehicle instrument characterized by being connected to a control output terminal (22) excluding a liquid crystal control output terminal. The vehicle speed display means is configured such that light is irradiated from the back surface side of the lens sheet (11) made of a translucent material by the light emitting diode (2),
The vehicular instrument according to claim 1 or 2, wherein the lens sheet is printed with a non-translucent substance in a region (13) excluding a portion (12) corresponding to the light emitting diode.

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