JPH0322998B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrical display device, and more particularly to a vehicle electrical display device suitable for use in the cabins of various vehicles.

(Prior Art) Conventionally, this type of electrical display device includes a detection means for detecting the operating state of an operating device mounted on a vehicle and generating this as a detection signal, and a detection signal based on the detection signal from this detection means. A calculation means for obtaining physical information about the vehicle and generating a drive signal necessary to define this physical information, and a display surface attached to a part of the peripheral wall of the vehicle interior of the vehicle and exposed inside the vehicle interior. and a display device that displays the physical information on its display surface by electroluminescence in response to a drive signal from the arithmetic means.

(Problem to be Solved by the Invention) However, with such a configuration, while the vehicle is running, the brightness near the display surface of the display device changes due to changes in the intensity of light that enters the vehicle interior through the vehicle window. Depending on the relationship between this change in brightness and the brightness of the display surface, the driver may feel dazzled or have difficulty seeing the display surface. The degree of this problem varies depending on the individual preferences and senses of each driver.

The present invention has focused on this, and provides an electrical display device for a vehicle that adjusts the brightness on the display surface according to changes in brightness near the display surface of the display device and the driver's preference. This is what I am trying to do.

(Means for Solving the Problems) In solving the above-mentioned problems, the structural features of the present invention include a detection means that detects the operating state of an operating device mounted on a vehicle and generates a detection signal;
an output signal generating means for calculating physical information regarding the vehicle based on the detection signal and generating it as an output signal; and a display surface that is attached to a part of the peripheral wall of the passenger compartment of the vehicle and is exposed in the passenger compartment. In an electrical display device comprising a display device that displays the physical information on the display surface by an electroluminescent effect in response to an output signal, the relationship between the intensity of light in the vicinity of the display surface of the display device an adjusting means that is operated by a driver to adjust a reference value of the brightness of the display surface according to the driver's preference; a photoconductor having a conductivity that changes according to a change in the intensity of light in the vicinity; a duty ratio that corresponds to an adjustment reference value of the adjustment means; and a duty ratio that corresponds to a change in the conductivity of the photoconductor. and a brightness signal generating means for digitally synthesizing a duty ratio corresponding to a brightness that is easy to see to the driver's preference, and generating a brightness signal at this duty ratio, the output signal generating means generating a duty ratio of the brightness signal. The present invention is characterized in that the output signal is generated at the ratio.

(Function) By configuring the present invention as described above, the reference value of the brightness on the display surface can be adjusted by operating the adjustment means in relation to the intensity of light near the display surface of the display device. When adjusted according to the driver's preference, the brightness signal generating means digitally adjusts the duty ratio corresponding to the adjustment reference value of the adjusting means and the duty ratio corresponding to the change in the conductivity of the photoconductor. A brightness signal is generated at this duty ratio by combining the signals and a duty ratio corresponding to easy-to-see brightness that suits the driver's preference, and the output signal generating means generates an output signal at the duty ratio of the brightness signal. The display displays the physical information on its display surface in response to the output signal.

(Effects of the Invention) As described above, according to the present invention, the duty ratio of the output signal can be adjusted to match the brightness of the photoconductor according to the driver's preference by adjusting the adjustment means unrelated to the photoconductor. Since the brightness is digitally synthesized to satisfy both the brightness that is easy to see and takes into account the change in conductivity of the Even if the brightness in the vicinity fluctuates over a wide range, the displayed content on the same display surface can be visually recognized at a brightness that suits the driver's preference without causing glare or difficulty in viewing. In addition, since the duty ratio corresponding to the output of the photoconductor and the duty ratio corresponding to the adjustment reference value of the adjustment means are digitally synthesized, the photoconductor is Fine adjustment is easy even when the body's output level is low, and it is less susceptible to external noise.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, an electrical speed display device for a vehicle according to the present invention configured as shown in FIG. An example is shown in which it is attached to an instrument panel 10 provided indoors. The electrical speed display device includes a speed calculation circuit 50 connected to the speed sensor 20, a variable resistor 30, and an optical sensor 4.
The speed sensor 20 detects the running speed of the vehicle and generates a pulse signal having a frequency proportional to the running speed. The speed calculation circuit 50 is composed of a counter formed by an integrated circuit, and counts the number of pulse signals generated from the speed sensor 20, and uses the counting result to calculate the number of pulse signals necessary to define the running speed of the vehicle (in this embodiment). (21 or less) display command signals. In addition, in FIG. 1, the reference numeral 11 indicates a protective cover with an aesthetically pleasing appearance.

The variable resistor 30 is installed in a position that is easy for the driver to operate in the cabin of the vehicle, and the resistance value of the variable resistor 30 determines the brightness on the display surface of the display device 80, which will be described later, according to the driver's preference. The standard value is set manually to match the standard value. The optical sensor 40 consists of a CdS mounted on the instrument panel 10 inside the protective cover 11,
It has an internal resistance value that decreases (or increases) as the received light intensity increases (or decreases). In this embodiment, this internal resistance value is maximum when the intensity of light received by the optical sensor 40 is zero;
is minimum when exposed to direct sunlight.

The luminance signal generation circuit 60 includes first and second oscillators 60a, 60b, and both oscillators 60a, 60.
The first oscillator 60a includes a capacitor 61 and a diode 64a connected in series to the variable resistor 30 to form a charging time constant circuit, and the variable resistor 3
A fixed resistor 63 and a diode 64b are connected in parallel to 0 and a diode 64a to form a discharge time constant circuit together with a capacitor 61. Further, the first oscillator 60a includes an inverter 62 made of an integrated circuit, and this inverter 62 has a hysteresis function and is connected in parallel to a fixed resistor 63 and a diode 64b. Therefore, in the first oscillator 60a, the inverter 62 repeats the inversion action based on its hysteresis function in accordance with the alternating charging and discharging actions of the charging time constant circuit and the discharging time constant circuit, and (in this example, the frequency corresponding to the repetition of
A first oscillation signal is generated at several KHz). In this case, the ratio of the high-level signal width to one wavelength in the first oscillation signal (ie, the duty ratio) increases (or decreases) as the resistance value of the variable resistor 30 increases (or decreases).

The second oscillator 60b includes a capacitor 65 connected in series to the optical sensor 40 to form a charging time constant circuit.
and a diode 68a, and a fixed resistor 67 and a diode 68b which are connected in parallel to the optical sensor 40 and the diode 68a and form a discharge time constant circuit together with the capacitor 65. Further, the second oscillator 60b includes an inverter 66 having the same configuration and function as the inverter 62, and the inverter 66 is connected in parallel to a fixed resistor 67 and a diode 68b. Therefore, in this second oscillator 60b, the inverter 66 is
In relation to the hysteresis function, the reversal action is repeated in accordance with the alternating charging and discharging action of the charging time constant circuit and the discharging time constant circuit, and the frequency corresponding to the repetition of the reversal action (in this embodiment, Number 10K
Hz) to generate a second oscillation signal. In this case, the duty ratio of the second oscillation signal increases (or decreases) in accordance with the increase (or decrease) in the internal resistance value of the optical sensor 40. AND gate 69 includes both oscillators 60a,
The luminance signal is generated by receiving the first and second oscillation signals from the oscillation signal 60b, and the duty ratio of the luminance signal changes according to changes in the duty ratios of the first and/or second oscillation signals.

Further, the electrical speed display device includes a speed calculation circuit 5
0 and a drive circuit 70 connected to the luminance signal generation circuit 60, and a display 80 connected to this drive circuit 70.
The drive circuit 70 includes a plurality of (21 in this embodiment) NAND gates 71, . . . , 71
and field effect transistors (hereinafter referred to as
(referred to as FET) 72, . . . , 72. However, it is located at the left end of the diagram.
The NAND gate 71 generates a low level signal when the brightness signal from the AND gate 69 and the display command signal from the leftmost output terminal in the figure of the speed calculation circuit 50 are both at high level, and when one of the brightness signal and the display command signal is A low level produces a high level signal. Also, each of the remaining NAND gates 71
It functions similarly to the NAND gate 71 described above in response to the brightness signal from the AND gate 69 and the display command signal from each of the remaining output terminals of the speed calculation circuit 50.

The FET 72 located at the left end in the figure is connected to the DC power supply V _DD (5V) at its drain terminal, and connected to the NAND gate 71 (located at the left end in the figure) at its gate terminal. It becomes conductive (or non-conductive) in response to a low level signal (or high level signal) of the source terminal, resulting in generation (or stop) of a drive signal from the source terminal. Further, each of the remaining FETs 72 is also connected to the DC power supply V _DD and each of the remaining NAND gates 71, and functions in the same manner as the FET 72 described above. As shown in FIG.
Instrument panel 1 exposed near 0
As shown in FIG. 2, three sets of 7-segment fluorescent display tubes are arranged on the inside of the display surface of this display 80 to provide a 3-digit digital display. . Therefore, each segment of the fluorescent display tube in this display 80 emits light intermittently in response to each drive signal from the drive circuit 70 corresponding to each segment, and the light emission time (in other words, the light emission brightness) ) increases (or decreases) in accordance with an increase (or decrease) in the frequency of generation of each drive signal based on an increase (or decrease) in the duty ratio of the luminance signal from the luminance signal generation circuit 60. In addition, in FIG. 2, symbols f ₁ and f ₂ indicate filament terminals.

In this embodiment configured as described above, when the vehicle is placed in a daytime running state and the device of the present invention is activated, a pulse signal having a frequency proportional to the running speed of the vehicle is generated from the speed sensor 20 and the speed is increased. It is applied to the calculation circuit 50. Then,
A speed calculation circuit 50 counts pulse signals from the speed sensor 20, generates a plurality of display command signals necessary to define the traveling speed of the vehicle, and applies them to the drive circuit 70. Further, the first oscillator 60a generates the first signal in cooperation with the variable resistor 30.
in response to a second oscillation signal from the second oscillator 60b generated in cooperation with the oscillation signal and the optical sensor 40;
A brightness signal is generated from the AND gate 69 and the drive circuit 7
Assigned to 0. However, at this stage, direct sunlight is not entering the inside of the protective cover 11, and in relation to the brightness near the optical sensor 40,
It is assumed that the internal resistance value of the optical sensor 40 is determined and the resistance value of the variable resistor 30 is set as a reference value according to the driver's preference. Therefore,
The duty ratio of the luminance signal from the AND gate 69 is defined by the respective duty ratios of the first and second oscillation signals, that is, the resistance value of the variable resistor 30 and the internal resistance value of the optical sensor 40.

Therefore, a plurality of display command signals from the speed calculation circuit 50 are sent to the drive circuit 70 corresponding to each of these signals.
A luminance signal generation circuit 60 is connected to each NAND gate 71 of
When given together with the luminance signal from
Each FET 72 corresponding to each of these NAND gates 71 is intermittently conductive in response to a low level signal generated from each NAND gate in relation to the duty ratio of the luminance signal, and these FETs 72 are in an intermittent conductive state. Each segment of the fluorescent display tube in the display 80 corresponding to the above is caused to emit light intermittently. This means that the display 8
0 means that the traveling speed of the vehicle is digitally displayed by the intermittent light emitting action of each segment of the fluorescent display tube described above. In other words, the intermittent light emission time of each segment of the fluorescent display tube in the display 80 is defined by the duty ratio of the luminance signal, and therefore the luminance on the display surface of the display 80 is lower than that in the vicinity of the optical sensor 40. The value is adapted to the driver's preference in relation to brightness, and as a result, the driver can easily and clearly view the display contents of the display 80 without feeling dazzled or having difficulty seeing.

Further, in such a state, for example, if direct sunlight is incident on the optical sensor 40, the internal resistance value of the optical sensor 40 decreases. Then, in response to the luminance signal generated from the AND gate 69 at the duty ratio specified by the decrease in this internal resistance value,
The intermittent light emitting time of each segment of the fluorescent display tube in the display device 80 is specified under the control of the drive circuit 70, and the brightness on the display surface of the display device 80 takes into account the incidence of direct sunlight in the vicinity of the optical sensor 40. The brightness changes to a value that matches the brightness. As a result, the driver can easily and clearly see the displayed content on the display 80 without feeling any difference in brightness between the display surface of the display 80 and its vicinity by adjusting the brightness according to the driver's preference. can be visually recognized. Note that the intermittent light emitting action of each segment of the fluorescent display tube of the display device 80 in the above description of the action is based on each oscillator 60a,
Since the oscillation frequency of 60b is high, it is perceived by the driver as a continuous light emitting effect.

In addition, in the above description of the operation, the vehicle is in a daytime running state, but this is not limited to this; for example, when the vehicle is in a nighttime running state, the display 80 (or 80
The display brightness in a) is adjusted according to beam light from an oncoming vehicle, direct light from a high-rise building, etc., and as a result, substantially the same effect as in the case described above can be achieved.

Further, in the above embodiment, an example in which CdS is used as the optical sensor 40 has been described, but instead of this, for example, CdSe or a phototransistor may be adopted as the optical sensor 40.

Further, in the above embodiment, an example in which the present invention is applied to an electrical speed display device for a vehicle has been described, but the present invention is not limited to this, and is applicable to an electrical display device that displays various physical information regarding the vehicle. It goes without saying that the present invention may also be implemented on the other hand. In this case, a liquid crystal display or a cathode ray tube display may be used instead of the display 80 (or 80a).

[Brief explanation of the drawing]

FIG. 1 is an external view showing an example in which the present invention is applied to an instrument panel in a vehicle interior, and FIG. 2 is an electric circuit diagram showing one embodiment of the present invention. Explanation of symbols, 10...Instrument panel, 20...Speed sensor, 30...Variable resistor,
40... Optical sensor, 50... Speed calculation circuit, 60
... Luminance signal generation circuit, 70 ... Drive circuit, 80
……display.

Claims (1)

[Claims] 1. A detection means for detecting the operating state of operating equipment mounted on a vehicle and generating it as a detection signal; an output signal generation means for calculating physical information regarding the vehicle based on the detection signal and generating it as an output signal; a display device that is attached to a part of the peripheral wall of the vehicle interior and has a display surface exposed in the vehicle interior, and displays the physical information on the display surface by an electroluminescent effect in response to the output signal; In the electrical display device, an adjusting means is operated in relation to the intensity of light in the vicinity of the display surface of the display device to adjust a reference value of the brightness of the display surface according to the driver's preference;
a photoconductor that is attached to a part of the peripheral wall of the vehicle compartment located near the display surface of the display device and has a conductivity that changes according to changes in the intensity of light near the display surface; and adjustment of the adjustment means. The duty ratio corresponding to the reference value and the duty ratio corresponding to the change in the conductivity of the photoconductor are digitally synthesized to obtain a duty ratio corresponding to easy-to-see brightness that meets the driver's preference. An electrical display device for a vehicle, comprising: a luminance signal generating means for generating a luminance signal, wherein the output signal generating means generates the output signal at a duty ratio of the luminance signal.