JP3339555B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device for displaying figures and characters using liquid crystal.

[0002]

2. Description of the Related Art A liquid crystal display device having a good response characteristic for displaying figures and characters corresponding to digital signals is known. 2. Description of the Related Art A liquid crystal display device uses an optical operation of a liquid crystal in which a polarization state is changed by applying a voltage, and a liquid crystal (a so-called segment) sealed in a small area divided into a predetermined range is converted into a digital signal. By energizing or de-energizing each range according to
Displays figures and characters. In addition, since the liquid crystal does not emit light by itself, figures and characters can be displayed using transmitted light or reflected light of a light source.

[0003] The driving method of the liquid crystal is generally static driving in which each segment is independently driven. However, since the number of connection terminals increases, a plurality of segments are combined to reduce the number of terminals and drive in a multiplex manner. In some cases, dynamic driving is performed. The response of the liquid crystal at low temperature is particularly deteriorated in the case of dynamic driving. For this reason, there has been proposed a liquid crystal electronic instrument panel having a good number of terminals and good low-temperature operation (Japanese Patent Laid-Open No. 59-195687).
Reference).

[0004]

However, in the conventional liquid crystal display device, figures and characters are displayed by the transmitted light or the reflected light from the time of turning on the light source. Therefore, when the display is started or the display contents are changed. The display may differ from the content. For example, when the display is switched, the display before the switching and the display after the switching may be mixed.

As shown in FIG. 9A, in a liquid crystal unit L composed of seven segments La, Lb, Lc, Ld, Le, Lf, and Lg, the transmitted light of the light source is determined by the combination of the energization of the segments La to Lg. Displays a number. FIG.
As shown in (2), when the segments Lb and Le are energized to display “1”, and then the segments La, Lc, Ld, Le and Lf are energized to change the display to “5”, the liquid crystal is According to the response characteristics, the segment Lb that should not be required for the display of “5” is in transition from the display of “1” (that is, the light is being switched to the transmissive state or the non-transmissive state due to de-energization), A state where "1" is displayed (a state where light is displayed in a transmitted state or a non-transmitted state) slightly remains. At the same time, the segments La, Lc, Ld,
The display of "5" is started by the energization of Le and Lf. As a result, the liquid crystal unit L is set to the segments La, Lb, L
c, Ld, Le, and Lf are displayed, and as a result, “9” is displayed. That is, "1",
"9" and "5" are displayed in this order. in this way,
While the display changes from “1” to “5”, the display of “9” which is originally unnecessary is made. This unnecessary display becomes worse during low-temperature operation.

An object of the present invention is to provide a liquid crystal display device capable of faithfully displaying information to be displayed without unnecessary display in consideration of the above fact.

[0007]

According to a first aspect of the present invention, there is provided a liquid crystal display device having a plurality of divided regions, and a light source for irradiating the liquid crystal unit with light. Means, setting means for setting the operation state of each region of the liquid crystal means to a transmission state in which light can be transmitted by energizing or de-energizing the liquid crystal means or a blocking state in which light transmission is suppressed; Control means for stopping irradiation of light from the light source means for a predetermined time when changing the operation state of each area of the liquid crystal means.

According to a second aspect of the present invention, in the liquid crystal display device according to the first aspect, the predetermined time is determined corresponding to a time of an unstable state while the operation state of the liquid crystal means is switched. Irradiation of light from the light source means is started after a lapse of a predetermined time.

According to a third aspect of the present invention, in the liquid crystal display device according to the second aspect, the predetermined time is determined according to a time of an unstable state of the liquid crystal means at a low temperature. I do.

According to a fourth aspect of the present invention, in the liquid crystal display device according to any one of the first to third aspects, the control means receives an instruction to change an operation state of the liquid crystal means from a command of light. It is characterized in that stopping the irradiation is started.

According to a fifth aspect of the present invention, in the liquid crystal display device according to the fourth aspect, the control means starts stopping light irradiation only at a low temperature.

According to a sixth aspect of the present invention, in the liquid crystal display device according to any one of the first to fifth aspects, the control means stops the irradiation of the light and controls the liquid crystal means. It is characterized in that energization is continued.

According to a seventh aspect of the present invention, in the liquid crystal display device according to any one of the first to sixth aspects, the control means stops the irradiation of the light and sets the liquid crystal means in advance. It is characterized in that the light-shielding state is set for the determined end time.

According to an eighth aspect of the present invention, in the liquid crystal display device according to any one of the first to seventh aspects, the light source means can independently irradiate a plurality of portions of the liquid crystal means with light. Wherein the control means stops light irradiation only in the area where the operation state of each area of the liquid crystal means is changed.

According to a ninth aspect of the present invention, in the liquid crystal display device according to the eighth aspect, the liquid crystal means is a vehicle speed display liquid crystal means having a plurality of vehicle speed display areas having a plurality of divided areas. It is characterized by.

According to a tenth aspect of the present invention, in the liquid crystal display device according to any one of the first to eighth aspects,
The liquid crystal means is an instrument liquid crystal means provided with an instrument display area for performing display corresponding to an in-vehicle instrument.

As shown in FIG. 1, in the liquid crystal display device according to the first aspect, the operating state of each area of the liquid crystal means having a plurality of divided areas is set by the setting means by energizing or de-energizing the liquid crystal means. A transmission state in which light can be transmitted or a blocking state in which transmission of light is suppressed is set. With the light from the light source irradiating the liquid crystal means, figures and characters corresponding to the transmission state or the blocking state of each area of the liquid crystal means are displayed. The control means stops the light irradiation of the light source means for a predetermined time when changing the operation state of each area of the liquid crystal means. The change of the operation state means a change of the display contents displayed by the liquid crystal means, and a change from the transmission state to the cutoff state, the change from the cutoff state to the transmission state, and the energization of the liquid crystal means for each area of the liquid crystal means. It includes the start of energization that is performed first to change to the transmission state or the cutoff state. Thus, when changing the operation state of each area of the liquid crystal means,
Since the light irradiation of the light source means is stopped for a predetermined period of time, when the operation state of each area of the liquid crystal means is changed, figures and characters due to light irradiation are not displayed, and unnecessary figures and characters are displayed. There is no.

The response characteristics of the liquid crystal means can be experimentally obtained, and the time of the unstable state during the switching of the operation state of the liquid crystal means can be determined from the response characteristics. Therefore, as described in claim 2, a predetermined time for stopping the irradiation of light from the light source means is determined in accordance with the time of the unstable state while the operation state of the liquid crystal means is switched, and the determined predetermined time is defined as By starting the light irradiation of the light source means after the elapse, the light irradiation is stopped for a time corresponding to the unstable state of the liquid crystal means, and unnecessary figures and characters are not displayed.

The response characteristics of the liquid crystal means are significantly deteriorated at low temperatures. Therefore, as described in claim 3, the predetermined time for stopping the irradiation of light from the light source means is determined in accordance with the time of the unstable state of the liquid crystal means at low temperature, so that the liquid crystal means can be operated in any temperature environment. However, the display of figures and characters in an unstable state of the liquid crystal means is suppressed, and the figures and characters to be displayed can be displayed faithfully.

To change the operation state of the liquid crystal means,
The control unit issues an instruction to change the operation state of the liquid crystal unit. After this instruction, the operation state of the liquid crystal unit is changed. Therefore, as described in claim 4, the control means includes:
By starting to stop the light irradiation from the instruction to change the operation state of the liquid crystal means, light is not irradiated at the time when the operation state of the liquid crystal means is changed, so the display of figures and characters on the liquid crystal means That is, the figures and characters to be displayed can be faithfully displayed without displaying unnecessary figures and characters. Since the response characteristic of the liquid crystal means deteriorates remarkably at a low temperature, the control means starts stopping the light irradiation only at a low temperature, so that the liquid crystal means can operate in any temperature environment. However, the display of figures and characters in an unstable state of the liquid crystal means is suppressed, and the figures and characters to be displayed can be displayed faithfully.

In order to display figures and characters, it is necessary to irradiate light from the light source means and to set a transmissive state or a cut-off state by energizing or de-energizing the liquid crystal means. In order for the liquid crystal unit to stably transition to the transmission state or the blocking state, it is preferable that the liquid crystal unit itself is activated. Therefore, as described in claim 6, the control means stops the light irradiation. At the same time, by continuing the energization of the liquid crystal means, since no light has been irradiated, figures and characters are not displayed on the liquid crystal means, but the liquid crystal means itself is activated by continuation of the energization,
The time for shifting to the stable state can be shortened.

The liquid crystal display device provided with the liquid crystal means terminates the display processing itself by turning off the power or the like. However, as described above, irradiation of light from the light source means and light emission from the liquid crystal means are required for displaying characters and figures. There is a correlation with transmission and blocking of light.
By the way, generally, the light source means takes some time from the lighting state to the light-out state in which light is not completely emitted, and afterglow is emitted during that time. For this reason, when the liquid crystal unit is in a transmission state or a cutoff state due to power interruption or the like and is in a state similar to the display of characters or graphics, if the afterglow is emitted from the light source unit, the display process is terminated. However, unnecessary characters and graphics are displayed. Further, even when there is no afterglow from the light source means, unnecessary characters or figures may be displayed as in the case of afterglow due to the incidence of external light such as sunlight. Therefore, as described in claim 7, the control means includes:
By stopping the light irradiation and setting the liquid crystal unit in the light-shielding state for a predetermined end time, unnecessary characters and figures are not displayed.

When changing the operation state of the liquid crystal means,
It is rare that all areas are changed, and the operation state of only a part of them is often changed. Therefore, as described in claim 8, the light source means can independently irradiate light to a plurality of portions of the liquid crystal means, and the control means can irradiate light only to an area where the operation state of each area of the liquid crystal means is changed. Is stopped, irradiation of light is stopped only in the area where the operation state is changed, and unnecessary figures and characters are not displayed.

Here, the speed of the vehicle is usually indicated by an hourly speed, and can be indicated by a numerical string of about three digits.
During stable running of the vehicle, the display of all digits is not changed, but a part thereof is changed. Therefore, claim 9
As described in the above, by using the liquid crystal means for the vehicle speed display liquid crystal means having a plurality of vehicle speed display areas having a plurality of divided areas, unnecessary speed display is not performed during the change of the vehicle speed, and the vehicle speed is controlled. A faithful display can be performed.

In many cases, the vehicle is in a low temperature environment or in an environment in which external light such as sunlight is directly irradiated. When the liquid crystal device is used in this vehicle, the response of the liquid crystal device depends on the environment. Due to the influence of characteristics and the like, unnecessary display is performed, and information to be displayed cannot be displayed faithfully. Therefore, as described in claim 10, by using the liquid crystal means for an instrument liquid crystal means having an instrument display area for displaying an instrument corresponding to an in-vehicle instrument, a low temperature environment where a vehicle exists or The information to be displayed can be displayed faithfully without unnecessary display regardless of the environment where external light such as sunlight is directly irradiated.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the present embodiment, the present invention is applied to a vehicle speed display device mounted on a vehicle.

As shown in FIG. 2, the vehicle speed display device 10 according to the first embodiment includes a control device 12, a temperature detector 34, a liquid crystal display 36, and a light source 38 connected to the control device. . The liquid crystal display 36 is composed of liquid crystal display units 36A, 36B, 36C of 7 segments each,
Digit display is possible. The liquid crystal display unit 36A is a display unit for displaying upper digits, the liquid crystal display unit 36B is a display unit for displaying middle digits, and the liquid crystal display unit 36C is a display unit for displaying lower digits. Although not shown, the liquid crystal display 36 is provided with a polarizing plate, and the light transmitted through the liquid crystal display 36 can be changed to a transmission state or a light shielding state by changing the light transmission state by energizing the liquid crystal. Configuration. The light source 38 includes a backlight 38
A, 38B and 38C. The backlight 38A is a light source for irradiating the liquid crystal display unit 36A with light, and the backlight 38B is a light source for irradiating the liquid crystal display unit 36B with light, and is for irradiating the liquid crystal display unit 36C with light. (See FIG. 3). By turning on these backlights 38A, 38B, 38C, each of the liquid crystal display units 36A, 36B, 36C can be displayed.

The control device 12 includes a CPU 14, a RAM 1
6, a microcomputer comprising a ROM 18, an input / output port (I / O) 20, and are connected by a bus 22 so that commands and data can be transmitted and received. The ROM 18 stores a processing routine described later.

The input / output port 20 of the control device 12 is connected to a temperature detector 34 via an amplifier 24 and to a liquid crystal display 36 via a driver 26.
The input / output port 20 is connected to a backlight 38A of a light source 38 via a driver 28. Similarly,
The input / output port 20 is connected to a backlight 38B via a driver 30 and to a backlight 38C via a driver 32. The control device 1
2 is connected to a battery via an ignition key cylinder of a vehicle (not shown) to supply power.

Next, the operation of the present embodiment will be described. It is assumed that the display instruction of the vehicle speed on the liquid crystal display 36 is started when the power supply to the control device 12 is started. The description of the setting of the display data (vehicle speed) on the liquid crystal display 36 is omitted.

When power is supplied to the control device 12 by an ignition key (not shown), a display instruction to the liquid crystal display 36 is started, the processing routine of FIG. 4 is executed, and the routine proceeds to step 100. In step 100, the temperature S is read by the temperature detector 34, and the next step 10 is executed.
2, the temperature S is a predetermined value (0 ° in the present embodiment).
C) It is determined whether or not the temperature is low by determining whether or not the temperature is below.

When S ≦ 0, the determination in step 102 is affirmative, and the routine proceeds to step 104 and waits until a predetermined time T1 has elapsed. Since the display of each liquid crystal display unit becomes unstable when the temperature of the liquid crystal display 36 is low, the elapsed time until the display of the liquid crystal display 36 becomes stable at the time of low temperature is determined in advance by an experiment. R as time T1
It is stored in the OM 18. Therefore, after the predetermined time T1 has elapsed, the display on the liquid crystal display 36 is stabilized even at a low temperature. In the next step 106, the backlight is turned on. Accordingly, even when the liquid crystal display 36 is unstable at a low temperature, the display by the backlight lighting is not performed, and the display by the backlight lighting is performed after the time when the display of the liquid crystal display 36 becomes stable. You. For this reason, the numbers to be displayed (for example,
By displaying “0”), the display quality of the liquid crystal display 36 can be improved.

On the other hand, when S> 0 (No in step 102), it is not necessary to consider the elapsed time until the liquid crystal display 36 becomes stable with respect to the temperature.
Then, the process proceeds to step S6, where the backlight is turned on, followed by terminating the present routine.

Next, a second embodiment will be described. In addition,
This embodiment has the same configuration as the above embodiment,
The same portions are denoted by the same reference numerals, and detailed description is omitted.

In the first embodiment, when the temperature of the liquid crystal display 36 is low, the backlight is turned on after a predetermined time T1 has elapsed, thereby stabilizing the display of the liquid crystal display 36. In the embodiment, the display response of the liquid crystal display 36 is improved.

When power is supplied to the controller 12 by an ignition key (not shown), the processing routine shown in FIG. 5 is executed, and after the temperature S is read (step 10).
0) In step 101, energization of the liquid crystal display 36 is started. Then, it is determined whether or not the temperature S is low (step 102). If the temperature S is low (S ≦ 0), the predetermined time T1
(Step 104), the backlight is turned on (step 106).

As described above, in the present embodiment, the liquid crystal display 36 is energized while waiting for the backlight to be turned on, and the liquid crystal molecules of each liquid crystal display section are activated (the liquid crystal molecules are activated). Operating state). For this reason,
The responsiveness of the liquid crystal molecules of the liquid crystal display 36 can be improved. In this manner, the response of the liquid crystal molecules can be improved, so that the display response of the liquid crystal display 36 can be improved, and the liquid crystal display
6 can be stabilized.

Next, a third embodiment will be described. In addition,
This embodiment has the same configuration as the above embodiment,
The same portions are denoted by the same reference numerals, and detailed description is omitted. In the present embodiment, the display content of the vehicle speed displayed on the liquid crystal display 36 is changed during acceleration or deceleration.

While the vehicle (not shown) is running, the interrupt processing routine of FIG. 6 is executed at predetermined time intervals. First, in step 110, the display data (vehicle speed) displayed on the liquid crystal display 36 is read to determine whether it is necessary to change the display content by acceleration or deceleration. If the display contents do not need to be changed, a negative determination is made in step 110, and the routine ends.

On the other hand, when the display contents need to be changed, an affirmative decision is made in step 110, and in step 112,
The temperature S is read by the temperature detector 34, and in the next step 114, the temperature S is set to a predetermined value (0 ° C. in the present embodiment).
It is determined whether or not the temperature is low by determining whether or not the temperature is below.

If S ≦ 0, the determination in step 114 is affirmative, and in step 116 the energization of the liquid crystal display 36 is cut off and the display is not displayed.
It waits until the predetermined time T2 has elapsed. As described above, since the display of each liquid crystal display unit of the liquid crystal display 36 becomes unstable at a low temperature, the elapsed time until the display of the liquid crystal display 36 becomes stable at a low temperature can be obtained by an experiment. The time required for stabilization for changing the display contents can be obtained, and the stable time is stored in the ROM 18 as the predetermined time T2. Then, after the predetermined time T2 has elapsed, the energization of each liquid crystal display is started in the next step 120. Therefore, after the predetermined time T2 has elapsed, the display before the change is not displayed on the liquid crystal display 36 even at a low temperature, and only the display after the change can be stably displayed. Thus, even when the liquid crystal display 36 is unstable at a low temperature, the display is not performed without an unnecessary number display (remaining portion display of the numbers before the change) due to the instability of the liquid crystal display 36. The display quality of the liquid crystal display 36 can be improved by displaying the changed number to be displayed.

On the other hand, when S> 0 (No in step 114), it is not necessary to consider the time until the liquid crystal display 36 becomes stable with respect to the temperature. Start and end this routine.

Next, a fourth embodiment will be described. In addition,
This embodiment has the same configuration as the above embodiment,
The same portions are denoted by the same reference numerals, and detailed description is omitted.

In the third embodiment, the liquid crystal display 36
When the display content is changed during acceleration or deceleration with respect to the vehicle speed displayed in (1), the power supply to the liquid crystal display 36 is cut off for a predetermined time T2 and is not displayed. Since the display is not displayed while the current is cut off, the display of the liquid crystal display 36 may flicker. In the present embodiment, the flicker is suppressed to a minimum.

Hereinafter, the operation of the present embodiment will be described. While the vehicle (not shown) is running, the interrupt processing routine of FIG. 7 is executed at predetermined time intervals, and it is necessary to change display contents by accelerating or decelerating by reading display data (vehicle speed) on the liquid crystal display 36. Determine the presence or absence (Step 1
10) If no change in the display content is required, step 11
If the answer is 0, the routine ends. When the display content needs to be changed (Yes at Step 110), the temperature S is read by the temperature detector 34 (Step 112), and it is determined whether the temperature S is low (Step 114).

If S ≦ 0 (YES at step 114), the routine proceeds to step 122, where the corresponding digit whose display content is to be changed is read. That is, a digit changed by acceleration or deceleration is read. In the next step 124, the energization of the liquid crystal display 36 for only the relevant digit whose display content is to be changed is cut off, and only the relevant digit is not displayed. Then, the process proceeds to step 118 and waits until the predetermined time T2 has elapsed. Next, a predetermined time T
After the lapse of 2, the energization of the liquid crystal display unit of the corresponding digit which is not displayed in the next step 126 is started. Therefore, after the predetermined time T2 has elapsed, the display before the change is not displayed on the liquid crystal display 36 even when the temperature is low, and only the display after the change can be stably displayed. Can be maintained as it is. Accordingly, even when the liquid crystal display 36 is unstable at a low temperature, only the digits whose display contents are to be changed should be displayed without unnecessary number display (remaining portion display of the numbers before the change). The number after the change is displayed, flickering can be suppressed, and the display quality of the liquid crystal display 36 can be improved.

On the other hand, if S> 0 (No in step 114), it is not necessary to consider the time until the liquid crystal display 36 becomes stable with respect to the temperature. Then, this routine ends. In this case, the energization may be started to the liquid crystal display unit of the corresponding digit which is not displayed, or the energization may be started to all the digits.

Next, a fifth embodiment will be described. In addition,
This embodiment has the same configuration as the above embodiment,
The same portions are denoted by the same reference numerals, and detailed description is omitted.

When the liquid crystal is in a non-energized state, the liquid crystal is in a transmissive state in which light is transmitted. That is, in the energized state, the liquid crystal display is blackened and a number is negatively displayed. In the liquid crystal display 36 for displaying (displaying), when the power supply of the vehicle speed display device 10 is stopped due to parking or the like and the display is terminated, the responsiveness of the liquid crystal molecules and the afterglow characteristic due to the turning off of the light source (light emission of the light source is completely Time characteristic before disappearing)
And unnecessary display may be made due to the afterglow. Further, the liquid crystal display 36 is directly irradiated with external light such as sunlight, and the display state may be the same as that of the display that does not require the liquid crystal display 36 due to the influence of the external light. In the present embodiment, unnecessary display when ending the display is minimized. Also, the liquid crystal display 36 has a black display on the liquid crystal display section in the energized state and the numbers are negatively displayed,
That is, the vehicle speed is displayed by blocking the light at the blackened portion and displaying the portion other than the light blocking.

While the control device 12 is energized, the interrupt processing routine of FIG. 9 is executed at predetermined time intervals. First, in step 130, it is determined whether or not an instruction to end the display is given by an operation such as turning off the ignition during parking or the like. If there is no instruction to end the display, step 130
Is negative, and this routine is terminated as it is.

On the other hand, when an instruction to end the display is given,
An affirmative determination is made in step 130, and the backlight is turned off in the next step 132. Thus, the liquid crystal display 36 is set to the non-display state. Next step 134
Now, all the liquid crystal display units 36A, 36A of the liquid crystal display 36
B and 36C are energized. This energization causes the liquid crystal display section of the liquid crystal display 36 to be blackened and shield light. In the next step 136, after waiting for a predetermined time T3,
In the next step 138, the energization of the liquid crystal display 36 is terminated, and the routine ends.

As described above, in the present embodiment, when the display is terminated, the liquid crystal display 36 is blackened so as to block the light. The display quality can be improved without unnecessary display due to the influence of external light such as sunlight directly applied to the liquid crystal display 36. Further, it is possible to suppress the occupant from erroneously recognizing the display based on the afterglow or the display based on the external light.

In the above embodiment, the case where the present invention is applied to the vehicle speed display device has been described. However, the present invention is not limited to this, and is applied to an in-vehicle instrument displaying alphanumeric characters and figures. can do.

[0054]

As described above, according to the first aspect of the present invention, when changing the operation state of each area of the liquid crystal means set by the setting means, the control means irradiates the light of the light source means. Is stopped for a predetermined period of time, so that even if the liquid crystal means is in an unstable operation state, the irradiation of light is stopped, and there is an effect that only figures and characters to be displayed can be faithfully displayed.

According to the second aspect of the present invention, the light irradiation is started after a predetermined time set in correspondence with the time of the unstable state while the operation state of the liquid crystal means is switched. During an unstable state, the irradiation of light is stopped and unnecessary figures and characters are not displayed, so that only the figures and characters to be displayed can be displayed faithfully.

According to the third aspect of the present invention, the irradiation of light is stopped for a predetermined time corresponding to the time of the unstable state of the liquid crystal means at a low temperature, and therefore, regardless of the temperature environment, There is an effect that figures and characters to be displayed can be displayed faithfully.

According to the fourth aspect of the invention, the control means starts stopping the light irradiation from the instruction to change the operation state of the liquid crystal means. There is an effect that the figure and the character to be displayed can be displayed faithfully without the light being unirradiated, and the unnecessary graphic and the character are not displayed.

According to the fifth aspect of the present invention, since the control means starts to stop light irradiation only at a low temperature, figures and characters to be displayed can be faithfully determined regardless of the temperature environment. Can be displayed on the display.

According to the sixth aspect of the present invention, since the control means stops the light irradiation and continues the energization to the liquid crystal means, there is no display on the liquid crystal means and the liquid crystal means itself continues the energization. And the time required for transition to the stable state can be shortened.

According to the seventh aspect of the present invention, the control means stops the light irradiation and sets the liquid crystal means in a light-shielding state, so that unnecessary characters and figures due to the incidence of external light such as sunlight can be eliminated. There is an effect that graphics and characters to be displayed can be faithfully displayed without being displayed.

According to the eighth aspect of the present invention, the control means stops the light irradiation only in the area where the operation state of each area of the liquid crystal means is changed, so that the area where the operation state is not changed is displayed as it is. There is an effect that unnecessary figures and characters are not displayed in the area where the operation state is changed while continuing, and the figures and characters can be faithfully displayed without a sense of incongruity.

According to the ninth aspect of the invention, by using the liquid crystal means for the vehicle speed display liquid crystal means having a plurality of vehicle speed display areas, unnecessary speed display is not performed during the change of the vehicle speed, and the vehicle speed is not changed. The display can be faithful,
This has the effect.

According to the tenth aspect of the present invention, by using the liquid crystal means for the instrument liquid crystal means having the instrument display area for displaying the information corresponding to the onboard instrument, a low temperature environment where the vehicle exists is provided. There is an effect that information to be displayed can be displayed faithfully without unnecessary display regardless of an environment where external light such as sunlight or sunlight is directly irradiated.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining a liquid crystal display device of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a vehicle speed display device according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a relationship between a liquid crystal display, a backlight, and a control device of the vehicle speed display device.

FIG. 4 is a flowchart illustrating a flow of a processing routine according to the first embodiment.

FIG. 5 is a flowchart illustrating a flow of a processing routine according to a second embodiment;

FIG. 6 is a flowchart illustrating a flow of a processing routine according to a third embodiment;

FIG. 7 is a flowchart illustrating a flow of a processing routine according to a fourth embodiment;

FIG. 8 is a flowchart illustrating the flow of a processing routine according to a fifth embodiment.

FIG. 9 is an explanatory diagram for explaining that an unnecessary display is performed when the display content is changed in a liquid crystal unit including seven segments.

[Explanation of symbols]

 Reference Signs List 10 vehicle speed display device 12 control device 34 temperature detector 34 36 liquid crystal display device 38 light source 38A, 38B, 38C backlight

Continuation of the front page (56) References JP-A-62-94828 (JP, A) JP-A-62-36640 (JP, A) JP-A-4-90656 (JP, A) JP-A-5-150746 (JP, A) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02F 1/133 535 G09G 3/18

Claims (10)

(57) [Claims] 1. A liquid crystal device having a plurality of regions divided in advance, a light source device for irradiating the liquid crystal device with light, and an operation state of each region of the liquid crystal device by energizing or de-energizing the liquid crystal device. Setting means for setting a transmission state in which light can be transmitted or a blocking state in which light transmission is suppressed; and when changing the operation state of each region of the liquid crystal means, the light irradiation of the light source means is performed for a predetermined time. A liquid crystal display device comprising: control means for stopping; 2. The method according to claim 1, wherein the predetermined time is determined corresponding to a time of an unstable state while the operation state of the liquid crystal unit is switched,
2. The liquid crystal display device according to claim 1, wherein irradiation of the light from the light source means is started after the predetermined time has elapsed. 3. The liquid crystal display device according to claim 2, wherein the predetermined time is determined corresponding to a time of an unstable state of the liquid crystal unit at a low temperature. 4. The control device according to claim 1, wherein the control unit starts stopping the light irradiation from an instruction to change an operation state of the liquid crystal unit.
A liquid crystal display device according to the item. 5. The control device according to claim 4, wherein the control unit starts stopping the light irradiation only at a low temperature.
3. The liquid crystal display device according to 1. 6. The liquid crystal display device according to claim 1, wherein the control unit stops irradiation of the light and continues energizing the liquid crystal unit. . 7. The control device according to claim 1, wherein the control unit stops the irradiation of the light and sets the liquid crystal unit in a light blocking state for a predetermined end time. A liquid crystal display device according to the item. 8. The light source means is capable of independently irradiating light to a plurality of portions of the liquid crystal means, and the control means irradiates light only to an area for changing an operation state of each area of the liquid crystal means. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is stopped. 9. The liquid crystal display device according to claim 8, wherein said liquid crystal means is a vehicle speed display liquid crystal means having a plurality of vehicle speed display areas having a plurality of divided areas. 10. The liquid crystal device for an instrument according to claim 1, wherein said liquid crystal device is a liquid crystal device for an instrument having an instrument display area for displaying an instrument corresponding to a vehicle instrument. 3. The liquid crystal display device according to 1.