JPS5992689A - On-vehicle color cathode-ray tube display device - Google Patents

Abstract

PURPOSE:To see a picture with good visibility day and night through simple constitution by controlling luminance, contrast, and color saturation of an on- vehicle color cathode ray tube associatively with the lighting switch of the vehicle. CONSTITUTION:While outdoor light is bright in the daytime and the lighting switch 1 of the vehicle is off, an interlocking switch 3 is also off and a transistor (TR)4 is off, so that no current is conducted through a relay coil 500 to open contacts 510, 520, and 530. When the outdoor light is scarece at night and the lighting switch is closed, the interlocking switch 3 is closed to conduct a current through the relay coil 500. Consequently, relay contacts 510, 520, and 530 are closed and the 2nd video amplifying circuit and color band amplifying circuit (not shown in a figure) vary resistance value to adjust to the optimum luminance and color saturation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an in-vehicle color cathode ray tube display device applied to, for example, a color television receiver or a color monitor used in a car, and in particular to control of brightness, contrast, and color saturation. It is something.

In conventional automotive color CRT display devices, even if the brightness, contrast, and color saturation are optimally adjusted during the day, the brightness of the image becomes too bright at night due to the dark outside light, resulting in a very dazzling screen. Become. Furthermore, if you try to lower the brightness manually, you will also have to make adjustments such as lowering the contrast and color saturation, which is not only cumbersome, but also extremely dangerous when driving.

This invention was made in view of the above circumstances, and when the car's lighting switch is closed when the outside light becomes dark, the brightness, contrast, and color saturation are automatically adjusted to the optimal level. The purpose is to provide a simple color cathode ray tube display device for in-vehicle use.

FIGS. 1 and 2 show an embodiment of the present invention. In Fig. 1, (1) is a lighting switch connected in series to a 12V power supply E, for example, (2) is a lamp for night illumination, and the lighting switch (2) is a lamp for night illumination.
1) By closing the lamp, the lamp for night illumination (
2) is now lit. (3) is a switch that is connected in series to the power source E and is closed in conjunction with the closing of the lighting switch (1). (4) is a transistor whose base is driven by the switch (3), (5) is a relay circuit driven by the transistor (4), a relay coil (500), and relay contacts (510), (520). ), (580), and each contact (510), (520).

(580) have contact output lines Al, At, and
As is connected, and when current flows through the relay coil (500), the contacts (510), (520), (
580) are each closed. The above switch (3),
) A transistor (4), a relay circuit (5), etc. constitute a switching circuit (100) that drives a control means to be described later.

FIG. 2 shows an example of a color monitor signal circuit. In the figure, Pi is a video signal input point, Pi is a first video amplification circuit, and (5) is a second video amplification circuit. This second
The video intensifier circuit (AI and A in ■ correspond to the contact output lines AI and A from the relay circuit (5) in Figure 1, and hl and A! respectively adjust the contrast and brightness. It's about to be controlled.

2 is a video output circuit connected to the second video intensifier circuit 2, which is composed of an in-phase amplifier. (The moth is a color band amplification circuit connected to the first image amplification circuit (10), 8.58
MH2±500 This is to amplify the KH2 color signal component. As in this color band amplification circuit (4) corresponds to the contact output line A3 from the relay circuit (5) in FIG. 1, and the color saturation is controlled by this As.

(50) is a color synchronization circuit connected to the color band amplification circuit (40), which takes out the burst signal and outputs the reference subcarrier 8.
．． It is designed to generate 58MHz. The image is a demodulation circuit that performs X-axis demodulation and two-axis demodulation using the signals from the color band amplification circuit (grasp) and color synchronization circuit (seki).
70) is a circuit that obtains R-Y, B-Y, and G-Y color difference signals from the X-axis and Z-axis outputs from the demodulation circuits, and is generally called a matrix circuit. (
The shaft is a color cathode ray tube.

The configuration of the brightness and contrast adjustment part in the second image amplification circuit (the control means (800)) will be explained with reference to FIG. 8. In the figure, Ql, Ch are image amplification transistors, VRl, VRz is a variable resistor for adjusting the video amplitude, that is, for adjusting the contrast.The variable resistor VR is a resistor that can obtain the optimum contrast corresponding to daytime brightness when the contact output line A1 mentioned above is open. and the other variable resistor V
Rl is set to a resistance value such that when the contact output line A1 is closed, an optimum contrast corresponding to nighttime brightness can be obtained.

VRs and VR4 are variable resistors for brightness adjustment, respectively. When the emitter voltage of the image amplifying transistor Q8 increases, the brightness decreases. For example, if a positive polarity video signal is now input to the base input of the video amplification transistor Q1, the application of this signal increases the entator voltage of the video amplification transistor Q3. When this emitter voltage rises, the collector voltage of the image amplifying transistor Qs rises, so the cathode ray tube (F
The cathode potential of gjI increases, which reduces the brightness. The variable resistor VRs is set to a resistance value that provides optimum brightness corresponding to nighttime brightness when the contact output line hs is closed, and the variable resistor V
R4 is contact output line A! The resistance value is set to provide optimal brightness corresponding to daytime brightness when the lens is open.

Next, the configuration of the color band widening circuit (color saturation adjustment part, that is, its control means (400)) in FIG. 2 will be explained with reference to FIG. Width transistor, T1 is 8.58MH2±500K
VRs, a band transformer that extracts the H2 component.

VR. is a color signal amplitude adjustment resistor, that is, a color saturation adjustment variable resistor. The variable resistor VRs is set to a resistance value that provides the optimum color saturation corresponding to daytime brightness when the contact output line AI mentioned above is open. is the aforementioned contact output line As
The resistance value is set to provide the optimum color saturation corresponding to nighttime brightness when the lens is closed.

In the car-mounted color cathode ray tube display device configured as described above, while the car's lighting switch (1) is open due to bright daytime outside light, the switch (3) linked thereto also remains open. .

Therefore, the transistor (4) also remains off, and no current flows through the relay coil (500), so the relay contacts (510), (520), and (580) are in an open state. These relay contacts (510), (520)
, (580) in the open state, the second image intensifying circuit (A, , A of FIG. 2) and A3 of the color band amplifying circuit (40) in FIG. 2 are each open. , in FIG. 8, when AI and A are open, the optimum contrast corresponding to daytime brightness is obtained by variable resistor VRl, and variable resistors VR3 and VR
4, it is possible to obtain the optimum brightness corresponding to daytime brightness, and when the above-mentioned A3 is open in FIG. . This provides optimal contrast during the daytime.
Brightness and color saturation will be obtained.

Next, when the lighting switch (1) of the vehicle is closed at night when the outside light is dark, the switch (3) linked thereto is closed. Therefore, the transistor (4) is turned on, current flows through the relay coil (500), and the relay contacts (510), (520), and (580) are closed. These relay contacts (510).

When (520) and (580) are in the closed state, the second image amplification circuit (AI, Am in (A) and A3 of the color band amplification circuit (40) in FIG. 2 are closed. That is, In FIG. 8, when the above At and As are in the closed state,
The optimum contrast corresponding to the brightness at night can be obtained by the variable resistors VRt and VR, and the optimum brightness corresponding to the brightness at night can be obtained by the variable resistor VRI. When is in the closed state,
The optimum nighttime saturation can be obtained with the variable resistors VR, , VR,. This results in optimal contrast, brightness and color saturation at night.

As described above, the present invention has a simple configuration that only includes a switching circuit that operates in conjunction with a lighting switch to drive the brightness, contrast, and color saturation control means of an automotive color cathode ray tube. The hassle of having to change the brightness adjustment between day and night is eliminated, and the brightness is optimal both day and night.
This has the effect that images can be viewed with good visibility under contrast and color saturation.

[Brief Description of the Drawings] Figs. 1 and 2 show an example of an in-vehicle color cathode ray tube display device according to the present invention. Fig. 2 is a block diagram showing an example of the signal circuit of a color monitor, Fig. 8 is an electric circuit diagram showing the specific configuration of the brightness and contrast adjustment means, and Fig. 4 is an electric circuit diagram showing the specific configuration of the color saturation adjustment means. It is a circuit diagram. (1)...Lighting switch, (100)...
switching circuit, (Boo)...contrast and brightness control means, (400)...color saturation control means,
E...Power supply. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) Figure 1 Figure 2 Vessel

Claims (1)

[Claims] (1) An in-vehicle color cathode ray tube display device comprising a lighting switch connected in series to a power source and a switching circuit that operates in conjunction with the lighting switch to control means for controlling brightness, contrast, and color saturation. .