JP3219216B2 - 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 for displaying information such as a message on a liquid crystal panel by light emitted from a backlight, and more particularly to a liquid crystal display device having excellent visibility in displaying emergency information.

[0002]

2. Description of the Related Art At present, at a work site such as a factory, a large number of liquid crystal display devices for displaying information such as various work procedures or operation statuses of work devices as messages are installed in order to achieve quick work and paperless operation. ing.

Therefore, in a conventional liquid crystal display device, FIG.
As shown in (a) and (b), a liquid crystal panel 81 is mounted on the front surface of the main body 80 where the window 80a is opened, and one side inside the main body 80 behind the liquid crystal panel 81 is irradiated with white light.
Backlight light source (hereinafter simply referred to as backlight)
U) is fixed and the backlight 82
, A light guide plate 83 is fixed directly below the window 80a,
A message is displayed on the liquid crystal panel 81 by light emitted from the backlight 82 via the light guide plate 83.

[0004] The liquid crystal display device installed at the work site displays an emergency message indicating a failure or an abnormality of the work equipment in addition to a steady message indicating the work procedure and the operation status of the work equipment. When the emergency message is displayed on the LCD, the emergency message can be displayed by displaying a larger than normal message, blinking, or operating the buzzer or indicator light attached to the LCD. To the public promptly and reliably.

[0005] Some conventional liquid crystal display devices include one shown in FIG.
As shown in FIG. 7, in addition to providing the liquid crystal panel 91 on the front panel 90a of the main body case 90, there are also provided ones provided with a plurality of LEDs 92. Has become.

For example, when the work equipment is in an abnormal operation mode such as an emergency stop, the LEDs 92 emit red light, and the emission color of the LEDs 92 allows the abnormality of the work equipment to be confirmed.

[0007]

However, in the above-described conventional liquid crystal display device, all messages are displayed only by the white light emitted from the backlight 82, so that an urgent message is displayed on the liquid crystal panel 81. However, the color of the message is the same as that of the stationary message, and for a worker far away from the liquid crystal display device, it is determined whether the stationary message is displayed on the liquid crystal panel 81 or the urgent message is displayed. There was a problem that it was difficult.

[0008] To solve this problem, a steady message and
It is also possible to display emergency messages in a different color
You. However, it is technically possible to display in different colors
However, in a compact liquid crystal display,
Because the cost is also limited, the display of any color
Display in a different color that is easy to see and distinguish
Was not easy.

Further, in the conventional liquid crystal display device provided with the LED 92 for displaying the operation mode, it is necessary to supply power to the LED 92 separately from the backlight.
ED92... Are point light sources, and have a problem that visibility from a distance is poor.

[0010]

[0011]

In view of the above, the present invention has been made in view of the above problems, and has excellent visibility in displaying an emergency message or the like by using a plurality of colors of light applied to a liquid crystal panel. It is another object of the present invention to provide a liquid crystal display device in which visibility of an operation mode is improved without increasing power consumption .

[0013]

According to a first aspect of the present invention, there is provided a liquid crystal panel comprising: a liquid crystal panel;
Is located behind the panel and directs the light incident on the entrance surface to the liquid crystal panel.
Light guide plate leading to the back of the panel and a first light source for irradiating light of a steady color
And light of a color different from the above-mentioned steady color.
The second backlight light source to be irradiated is connected to the light guide plate.
A first and a second buckler disposed on the light guide plate,
Backlight light source device that receives the light emitted by the light source
And commands from work equipment installed at the work site such as a factory.
Steady-state information indicating the operating status of work equipment, etc., based on signals
Is displayed, the first backlight light source is turned on, and
When displaying emergency information indicating malfunctions or abnormalities of industrial equipment
Bar that switches the second backlight source to light up
Backlight switching means, and a first backlight light source.
And irradiate the liquid crystal panel among the second backlight light sources.
The backlight source that emits light that increases the brightness
Low brightness when illuminating the LCD panel close to the panel
Backlight light source that emits light
Displayed on the LCD panel
A feature is to reduce a luminance difference between the steady information and the emergency information .

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

According to the first aspect of the present invention, first, the steady color light emitted from the first backlight reaches the rear surface of the liquid crystal panel via the light guide plate, so that the liquid crystal panel is in a steady color and steady state. Display information.

Then, for example, when an instruction to display a message or the like that conveys urgent information is given while the steady information is being displayed by the irradiation light from the first backlight, a backlight switching circuit or the like is activated. When the backlight switching means switches from the first backlight to the second backlight, the second backlight
The backlight emits light of a color different from the above-mentioned steady color, and this light reaches the rear surface of the liquid crystal panel via the light guide plate. Brightness of different colors between steady colors of LCD panel
The degree of difference is small, and the LCD panel displays
And message can reliably visually recognize that there is a change in the message is displayed information to convey emergency information Ru good different colors of light with constant color.

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the liquid crystal display device according to the present invention will be described below in detail with reference to the drawings.

[0038]

FIG. 1 is a sectional view showing an embodiment of the liquid crystal display device of the present invention .

In this figure, the liquid crystal display device has a first backlight 2 and a second backlight 3 for irradiating different colors behind a liquid crystal panel 1 for displaying a message or the like. Light emitted from the first and second backlights 2 and 3 is applied to the back surface 1a of the liquid crystal panel 1.
Light guide plate 4 is also arranged behind the liquid crystal panel 1,
The first and second backlights 2 and 3 are connected to a backlight switching circuit 5 that switches the operation of the two backlights 2 and 3 according to information such as a message.

Such a liquid crystal display device is mainly used at a work site to inform a worker of a work procedure, an operation state of work equipment, and the like as a message.

The liquid crystal panel 1 is formed in a rectangular shape having liquid crystal therein, and generates a light transmitting portion and a light blocking portion by changing the state of the liquid crystal, and also forms an outline image of characters and the like by both portions. Display surface 1 as a diagram of messages, figures, etc.
b.

The first backlight 2 is composed of an elongated cold-cathode tube that emits white light.
Behind and one side offset.

The second backlight 3 is composed of an elongated cold cathode tube similar to the first backlight 2, but emits red light unlike the white light emitted by the first backlight 2. Is what you do. The second backlight 3 is arranged at the same position as the first backlight 2 so as to be parallel to the first backlight 2, but the liquid crystal panel is located at a position higher than the position of the first backlight 2. It is arranged at a position close to 1. The first and second backlights
The set of (2) and (3) is called a backlight light source device here.
U. The light guide plate 4 is formed by printing a halftone dot pattern on an acrylic plate. The light guide plate 4 receives light emitted from the first and second backlights 2 and 3 from the side surface 4a and the back surface 4b to form a back surface of the liquid crystal panel 1. 1a.

Therefore, the irradiation light from the first and second backlights 2 and 3 is directly incident on the side surface 4 a of the light guide plate 4, but is reflected on the back surface 4 b behind the light guide plate 4. Irradiation light from the first and second backlights 2 and 3 enters through the plate 6.

FIG. 2 is a simplified circuit diagram of the backlight switching circuit 5 in this embodiment. As shown in FIG.
A first switch 5a for separately turning on / off the first and second backlights 2 and 3 connected in parallel to each other;
And a first switch 5b based on a command signal A output from an external device (not shown).
The first backlight 2 is turned ON / OFF by opening / closing a.
The second backlight 3 is turned on / off by turning off and opening / closing the second switch 5b based on a command signal B output from an external device.

Next, the operation of the liquid crystal display device according to this embodiment will be described.

First, it is assumed that a steady message such as a work procedure is displayed on the liquid crystal panel 1 by white light emitted from the first backlight. That is, it is assumed that the first switch 5a of the backlight switching circuit 5 is closed and the second switch 5b is open.

In this state, a steady message is displayed on the liquid crystal panel 1 with white as the background color or the outline color. During this display, an emergency message indicating a failure or abnormality of the work equipment is displayed on the external equipment. When a command is issued from the external device, command signals A and B are also transmitted from the external device to the backlight switching circuit 5.

Then, based on the command signals A and B, the first
When the switch 5a is opened from the closed state and the second switch 5b is closed from the open state, the first backlight 2 is turned off and the second backlight 3 is turned on, contrary to the conventional state. Turns ON.

Therefore, the liquid crystal panel 1 has “failure” or “abnormality” due to the red light emitted from the second backlight 3.
Will be displayed.

Further, since the second backlight 3 for irradiating red light is arranged at a position closer to the liquid crystal panel 1 than the first backlight 2 for irradiating white light, the red light is The message that reaches the rear surface 1a of the panel 1 uniformly and is displayed on the liquid crystal panel 1 is displayed in red with uniform brightness.

Therefore, according to this embodiment, when an emergency message is displayed on the liquid crystal panel 1, the emergency message is displayed by the red light, so that the emergency message is displayed on the liquid crystal panel 1 from a distance where the message cannot be read. It can be visually confirmed that the message is displayed.

The second backlight 3 for irradiating red light having a long wavelength is arranged at a position closer to the liquid crystal panel 1, and the red light reaches the rear surface 1 a of the liquid crystal panel 1 uniformly. , Emergency messages can be displayed evenly in red.

[0055]

FIG. 3A is a perspective view showing another embodiment of the liquid crystal display device suitable for the present invention , and FIG. 3B is a sectional view showing a section taken along line XX in FIG. It is.

The liquid crystal display device in this figure has a configuration similar to that of the liquid crystal display device shown in FIG. 1, except that a liquid crystal panel 10 is mounted on the front surface of the main body 11 and the first and the second liquid crystal panels are provided inside the main body 11. Second backlight 12, 13
(Backlight light source device) , and a light guide plate 14 for guiding light emitted from the first and second backlights 12 and 13 to the liquid crystal panel 10 is also disposed inside the main body 11.

Further, the first and second backlights 1
The housings 2 and 13 are housed in a case 15 detachable from the main body 11, and a backlight switching circuit (not shown) is also built in the main body 11.

Next, the structure of the liquid crystal display device will be described in more detail. The liquid crystal panel 10, the first and second backlights 12, 13, the light guide plate 14, and the backlight switching circuit are the same as those of the previous embodiment. The description is omitted because it is the same.

The main body 11 is formed in a frame shape with four side surfaces 11a as frames.
A window 11 through which light emitted from the first and second backlights 12 and 13 passes,
b is formed.

Further, the light guide plate 1 is located immediately below the window 11b.
4, a case 15 accommodating the first and second backlights 12, 13 is inserted beside the light guide plate.

The case 15 is elongated and has a U-shaped cross section for accommodating two first and second backlights 12 and 13, and has an opening 15 a facing the light guide plate 14 and a side surface of the main body 11. 11a is inserted.

FIG. 4 is a perspective view showing the case 15 from behind. As shown in FIG.
.., 15b connected to the electrodes of the first and second backlights 12, 13 are exposed, and the upper surface 15c of the case 15 is attached to the main body 11 at the time of insertion. Is provided with a snap 15d having a projection that engages with a hole (not shown) provided inside the
When the case 15 is attached to the main body 11,
,..., 15b are configured to contact metal fittings (not shown) provided inside the main body 11.

The metal fittings provided inside the main body 11 are as follows:
It is connected to an AC power supply via a backlight switching circuit.

Next, the operation of the liquid crystal display device according to this embodiment will be described. The description of the same operation as that of the previous embodiment is omitted, and the operation when the backlight is attached will be described.

First, the first and second backlights 12,
When the lamp 13 stops lighting, the first and second backlights 12 and 13 are separated from the main body 11 by pulling out the case 15 from the side surface 11 a of the main body 11.

Then, after removing the backlight which is no longer lit from the case 15, a new backlight is stored in the case 15, and the case 15 containing the new backlight is again removed from the side surface 11 a of the main body 11. insert.

Then, the projection of the snap 15d is engaged with the hole provided inside the main body 11, and the case 15 is
, And the installation of the backlight is completed.

Therefore, according to this embodiment, the same effects as those of the previous embodiment can be obtained, and in addition, the first and second embodiments can be realized.
The backlights 12 and 13 are housed in a case 15 detachable from the main body 11, and the mounting of the backlight is completed only by inserting the case 15 into the main body 11, so that the liquid crystal panel 10 and the main body Apart from this, it is possible to easily replace only the backlight.

[0070]

FIGS. 5A and 5B are cross-sectional views showing another embodiment of the liquid crystal display device suitable for the present invention .

In this figure, the liquid crystal display device has a first and a second
Although the backlights 21 and 22 (backlight light source device) and the light guide plate 23 are arranged, and the printed circuit board 24 forming the backlight switching circuit is also arranged behind the liquid crystal panel 20, but in FIG. A first backlight 21 for irradiating white light is disposed on one side surface 23a of the light guide plate 23 at a position close to the liquid crystal panel 20 and a second backlight 21 for irradiating red light. Light 2
Reference numeral 2 denotes one of the side surfaces 23 a of the light guide plate 23, like the first backlight 21, and is disposed at a position far from the liquid crystal panel 20.

In FIG. 7B, the first and second backlights 21 and 22 are provided on both side surfaces 23 of the light guide plate 23.
Two are arranged on the sides a and 23a so as to face each other.

That is, as shown in FIGS. 7A and 7B, the second backlight 22 that irradiates red light is more effective on the liquid crystal panel 20 than the first backlight 21 that irradiates white light. It is located at a position far away from.

Therefore, the first and second backlights 2
Comparative evaluation of luminance was performed by changing the positions of Nos. 1 and 22.

FIG. 6 is a cross-sectional view showing the structure of a liquid crystal display device for comparing and evaluating the luminance.
The first backlight 21 and the second backlight 22 are arranged at the position of. In addition, in order to facilitate luminance measurement,
Instead of the liquid crystal panel 20 shown in FIG. 5, a diffusion plate 25 for diffusing light is adopted, and a reflection film 26 is provided on the side other than the side surface 23a of the light guide plate 23 facing the backlights 21 and 22. Reflector 2 on back 23b of
7 is provided.

First, a first backlight 21 irradiating white light to A and a second backlight 22 irradiating red light to B shown in FIG.
Assuming that the case of turning on / off 22 is Experiment (1), the following measurement results of the luminance were obtained in the diffusion plate 25.

[0078]

[Table 1] Next, a second backlight 22, which irradiates A with red light,
Then, when the first backlight 21 for irradiating white light to B is arranged, and the two backlights 21 and 22 are turned on / off as an experiment (2), the following luminance measurement results are obtained on the diffusion plate 25. was gotten.

[0079]

[Table 2] As a result, in Experiment (1), the luminance difference between white light and red light was 27 [cd / m ² ], and in Experiment (2), the luminance difference between white light and red light was 100 [cd / m ² ]. The second backlight 22 irradiating red light is changed to the first backlight 22 irradiating white light.
The brightness difference becomes smaller when the backlight is disposed farther from the diffusion plate 25 than the backlight.

As a result of the comparative evaluation based on the above experiments (1) and (2), according to this embodiment, similar to the experiment (1), the luminance at which the liquid crystal panel 20 is irradiated on the liquid crystal panel 20 is measured.
Since the second backlight 22 that irradiates red light whose luminance irradiates the liquid crystal panel 20 becomes lower at a position farther than the first backlight 21 of white light whose white light becomes higher , white light and red light The difference in luminance of light is reduced, and both red and white colors can be displayed brightly on the liquid crystal panel 20.

Next, another liquid crystal display device suitable for the present invention will be described.
An example will be described. The description of the same configuration and operation as in the above-described embodiment will be omitted.

FIG. 7 shows a liquid crystal display device suitable for the present invention .
FIG. 8 is a perspective view showing another embodiment, and FIG. 8 is a sectional view showing a section taken along line XX in FIG.

The liquid crystal display device shown in FIGS.
A liquid crystal display window 31 and a transmission window 32 are opened in the front panel 30a of the LCD panel 30. A liquid crystal panel 33 and a light guide plate 34 are disposed behind the liquid crystal display window 31, and the transmission window 32 The first and second backlights 3 are positioned behind the light guide plate 34 and on one side 34a side of the light guide plate 34.
5, 36 (backlight light source device) are arranged.

The transmission window 32 is formed in an elongated shape according to the shape of the backlight, and can be regarded as a surface light source by emitting light.

Further, a printed wiring board 37 incorporating a backlight switching circuit and the like are disposed behind the light guide plate 34.

In such a liquid crystal display device, when a steady message is displayed on the liquid crystal panel 33, the first backlight 35 is turned on and the second backlight 36 is turned off.
The white light of the first backlight 35 reaches the liquid crystal panel 31 via the light guide plate 34, and a message is displayed with the white light.

At this time, the white light of the first backlight 35 is directly guided to the outside of the main body case 30 via the transmission window 32. However, when the first backlight 35 is ON, the work equipment and the like are turned off. Since no failure or abnormality has occurred in the transmission window 32, the white light visually recognized from the transmission window 32 is light according to the normal operation mode indicating the operation status of the work equipment and the like.

On the other hand, when an emergency message is displayed on the liquid crystal panel 33, the first and second backlights 35 and 36 are displayed.
The ON / OFF state is reversed from the above, and a message is displayed on the liquid crystal panel 33 by the red light of the second backlight 36.

At this time, the red light of the second backlight 36 is guided to the outside of the main body case 30 via the transmission window 32, but when the second backlight 36 is ON, the work is performed. The device or the like has a failure or abnormality, and the red light visually recognized from the transmission window 32 is light according to the abnormal operation mode of the working device or the like.

Therefore, according to this embodiment, the first and second backlights 35 and 36 are used to display the operation mode of the work equipment and the like without using the LED as in the related art.
The light corresponding to the operation mode can be emitted from the transmission window 32 using the light of LE.
Since the power consumption is reduced as compared with the case where D is provided, and the light in the transmission window 32 is captured as light from the surface light source, the light in the transmission window 32 can be visually recognized even from a distance.

Next, FIG. 9 is a sectional view showing another embodiment. The liquid crystal display device according to this embodiment has a scatterer that scatters light to the transmission window 32 shown in FIG. 7 and FIG. A plastic body 38 is provided.

The plastic body 38 scatters light in various directions due to surface cutting or the like, and is mounted so as to protrude from the surface of the front panel 30 a of the main body case 30 and cover the entire transmission window 32.

In such a liquid crystal display device, the light of the first and second backlights 35 and 36 is scattered in various directions by transmitting through the plastic body 38 through the transmission window 32, and thus is transmitted. The light emitted from the transmission window 32 can be visually recognized even from the lateral direction of the window 32, that is, from the side of the front panel 30a of the main body case 30.

[0094]

FIG. 10 is a sectional view showing another embodiment of the liquid crystal display device suitable for the present invention .

In the liquid crystal display device shown in this figure, a liquid crystal panel 42 is provided in a liquid crystal display window 41 of a main body case 40, and a diffusion plate 43 is provided behind the liquid crystal panel 42.
The light guide plate 44 is disposed with the light guide plate 4 interposed therebetween.
A reflection plate 45 is disposed behind the reflection plate 4.

Further, in this liquid crystal display device, a sidelight system is adopted, and one backlight 46 for irradiating white light is provided with an incident surface 44 a which is one side surface of the light guide plate 44.
The backlight 46 is turned on / off by a backlight lighting circuit 47.
It has been turned off.

Further, the backlight 46 and the incident surface 44a
A liquid crystal shutter 48 for partially blocking or passing the white light of the backlight 46 through the shutter surface halves 48a and 48b is disposed between the shutter control circuit 49 and the liquid crystal shutter 48. The shutter surface halves 48a and 48b are light blocking surfaces or light passing surfaces, and are located at positions facing one of the shutter surface halves 48a.
That is, a red filter 50 that converts white light into red transmitted light of an emergency color is provided on a half of the incident surface 44 a of the light guide plate 44.

Next, the operation of the liquid crystal display device according to this embodiment will be described.

First, when the power is turned on, the backlight 46 is always turned on by the backlight lighting circuit 47 and emits white light. In this state, when displaying a steady message on the liquid crystal panel 42, the shutter Control circuit 49
, One shutter surface half 48a of the liquid crystal shutter 48 is a light blocking surface, and the other shutter surface half 48b is a light passing surface.

As a result, the white light emitted from the backlight 46 passes through only the other shutter surface half 48b serving as the light passing surface and passes through the red filter 50 without passing through the red filter 50 to the incident surface 44a of the light guide plate 44. Incident.

Then, the light incident on the half of the incident surface 44 is
The light reaches the liquid crystal panel 42 via the light guide plate 44, the reflection plate 45, and the diffusion plate 43, and a steady message is displayed on the liquid crystal panel 42 by white light.

As described above, while displaying a steady message on the liquid crystal panel 42 with white light as a display color, the shutter control circuit 49 receives a display color switching signal indicating that an emergency message is displayed from work equipment (not shown) or the like. Then, in contrast to the case where the steady message is displayed, the shutter control circuit 49 sets one shutter surface half 48a of the liquid crystal shutter 48 in reverse.
Is a light passing surface, and the other shutter surface half 48b is a light blocking surface.

As a result, the white light emitted from the backlight 46 passes through only one half of the shutter surface 48a, which has become the light passage surface, and then passes through the red filter 50 to become red light to become the light guide plate 44. Incident on the half of the incident surface 44 of

The red light reaches the liquid crystal panel 42 in the same manner as the white light, so that the liquid crystal panel
An emergency message is displayed by the red light.

Therefore, according to this embodiment, two colors can be displayed with one backlight 46 and the backlight 4
Backlight lighting circuit 47 for controlling ON / OFF of 6
Since only one backlight is used, it is possible to reduce the size and space of the device as compared with a device that displays two colors with two backlights.

The shutter control circuit 49 alternately switches the shutter halves 48a and 48b of the liquid crystal shutter 48 between the light blocking surface and the light passing surface at high speed, thereby producing an effect similar to flicker. An urgent message can be displayed on the liquid crystal panel 42 by blinking red and white.

FIG. 11 is a sectional view showing another embodiment of the present invention .

The same components as those shown in FIG. 10 are denoted by the same reference numerals, and description thereof will be omitted.

In the liquid crystal display shown in this figure, a tubular drum 51 surrounding the entire outer periphery of the backlight 46 is provided.
The drum 51 is provided with a backlight 46.
And a part of the peripheral surface of the drum 51 has an elongated through-hole 51a that allows white light of the backlight 46 to reach half of the incident surface 44a of the light guide plate 44.
Is open.

Further, the drum 51 has a drum control circuit 5 such that the through hole 51a and one half of the incident surface 44a face each other.
2.

Further, one incident surface 44a of the light guide plate 44
One half is provided with a red filter 53 for emergency color display, and the other half of the incident surface 44a is provided with a green filter 54 for steady color display.

Next, the operation of the liquid crystal display device according to this embodiment will be described.

First, when a steady message is displayed on the liquid crystal panel 42, the drum control circuit 52 rotates the drum 51 so that the through hole 51a of the drum 51 and the green filter 54 face each other.

As a result, the white light emitted from the backlight 46 passes through the through-hole 51a while passing through the green filter 5.
4 also passes through to become green light, and the green light reaches the liquid crystal panel 42 via the light guide plate 44, the reflection plate 45, and the diffusion plate 43, and a steady message is displayed on the liquid crystal panel 42 by the green light. You.

When the drum control circuit 52 receives a display color switching signal from work equipment (not shown) while displaying a steady message in green light, the drum control circuit 52
The drum 51 is rotated so that the through-hole 51a faces the red filter 53.

As a result, the white light that has passed through the through-hole 51a passes through the red filter 53 and becomes red light, and when this red light reaches the liquid crystal panel 42, an urgent message is sent to the red light. Is displayed.

Therefore, according to this embodiment, two colors can be displayed by one backlight 46 as in the above-mentioned embodiment, and only one backlight lighting circuit 47 is provided. The device can be reduced in size and space can be saved as compared with a device that performs two-color display using a light.

Next, FIG. 12 is a schematic diagram showing another embodiment of the present invention .

The liquid crystal display device 60 shown in this figure is the same as that of the above-listed embodiment.
0, a rotation indicator light (patlite (trademark)) 62 as an alarm via a rotation indicator light control interface 61
Is connected.

The operation of this embodiment will be described. First, the backlight switching circuit, the shutter control circuit, or the drum control circuit of the liquid crystal display device 60, when displaying an urgent message, displays from an unillustrated work equipment or the like. receiving color switch signals, but this display color switching signal rotation display
It is also received by the light control interface 61. By rotating the display lamp control interface 61 which receives the display color switching signal actuates the rotation indicator 62, and the rotary indicator 62 while displaying an emergency message by the red light in the liquid crystal display device 60 is operated Become.

Therefore, according to this embodiment, the rotation indicator light 62 is activated in addition to the display of the emergency message by the red light, so that an operator who is working away from the liquid crystal display device 60 may have an emergency. Can be notified.

[0123]

FIG. 13 is a block diagram showing another embodiment of the present invention .

The liquid crystal display device shown in this figure includes a liquid crystal panel and a light guide plate (not shown) having the same configuration as that of the liquid crystal display device of FIG. 1, and has a white backlight 70 for irradiating white light and a red light. A red backlight 71 for irradiating is provided, and further, a white and red lighting circuit 72, for lighting the white and red backlights 70, 71 with AC power, respectively.
73, a white and red lighting switch 7 provided between a connection line between each of the white and red lighting circuits 72 and 73 and the DC power supply 74
5,76, ON / O of white and red lighting switches 75,76
It has a switch control unit 77 for controlling the FF.

The white and red backlights 70 and 71
Is disposed close to a dark place in the apparatus main body.

The switch control unit 77 switches ON / OFF of the white and red lighting switches 75 and 76 based on a command signal, and according to the switching operation of the switch control unit 77, the white and red backlights 70 and 76 are switched. As the 71 switches, the display color of the LCD panel changes from white to red,
Or it will switch to the contrary.

When turning on the red backlight 71, the switch control section 77 turns on the red lighting switch 76.
After that, the white lighting switch 75 is turned on for a predetermined time, and this operation will be described in detail in the following operation description.

Next, the operation for turning on the red backlight 71 will be described with reference to FIGS.

FIG. 14 is a flowchart showing a processing procedure when the red backlight 71 is turned on, and FIG.
6 is a time chart showing a switching timing to the operation.

As shown in FIG. 14, first, when the white backlight 70 is turned on (STEP 100), the switch control unit 77 determines whether or not there is a red light command (STEP 110). If not (ST
(EP110 "NO"), the state of STEP100 is maintained.

On the other hand, if there is an instruction to turn on red (STE
P110 “YES”), the switch control unit 77 turns on the red lighting switch 76 while keeping the white lighting switch 75 ON.
By setting N, the red backlight 71 is turned on (STEP 200).

Accordingly, the white and red backlights 70,
Simultaneous lighting of the red backlight 71 is continued, and the periphery of the red backlight 71 is illuminated by the white light of the white backlight 70, so that the dark effect that occurs when the red backlight 71 is turned on is eliminated.

Thereafter, the switch control section 77 determines whether or not a time required for the red backlight 71 to be completely turned on from the start of lighting, for example, 300 [ms], has passed a preset time. (STEP 210), 30
After the elapse of the set time of 0 [ms] (STEP 210 “YE
S ″), the white lighting switch 75 is turned off, and the white backlight 70 is turned off (STEP 220).

That is, as shown in FIG.
The timing of switching from the white backlight 70 to the red backlight 71 is determined by turning on the red backlight 71 → a predetermined time t.
The process is performed in the order of progress → turning off of the white backlight 70.

Here, the predetermined time t is set in advance to a very short time of 300 [ms] as exemplified above, and is used for simultaneously turning on the white and red backlights 70 and 71. The set time.

On the other hand, when the white backlight 70 is off (STEP 105), the switch control unit 77
The same determination as in STEP 110 is performed (STEP 11
5) If there is no instruction to light red (STEP “N
O ″), the state of STEP 105 is maintained again.

Then, if there is an instruction to light red (ST
EP 115 “YES”), the switch control unit 77 turns on the white lighting switch 75 before turning on the red lighting switch 76, thereby turning on the white backlight 70 (STEP 125).

After a certain period of time has elapsed since the white backlight 70 was turned on, the switch control unit 77 performs the processing after STEP 200 to eliminate the dark / dark effect when the red backlight 71 is turned on, as described above.

Therefore, according to this embodiment, when the red backlight 71 is turned on, the red backlight 7
1 and the white backlight 70 are simultaneously turned on for a predetermined period of time, and the periphery of the red backlight 71 at the time of lighting is brightened by the white light of the white backlight 70 to eliminate the so-called dark effect. Can be turned on quickly, and the display color of the liquid crystal panel switches smoothly from white to red.

Next, another embodiment of the present invention will be described. This embodiment is almost the same as the above embodiment,
In addition to the white backlight 70 shown in FIG. 13, an illumination light source such as an LED that illuminates the periphery of the backlight 71 is provided. Lighting switch is also ON
/ OFF.

Further, the switch control section 77 performs the processing after STEP 105 in the flowchart of FIG. 14 on the irradiation light source instead of the white backlight, and can exert the same effect as the above-described embodiment.

Although the above-described embodiment is a liquid crystal display device capable of displaying two colors, three or more colors can be obtained by increasing the number of backlights or color filters or by dividing the shutter surface of the liquid crystal shutter into three or more. Can also be displayed.

[0144]

As is apparent from the above description, according to the present invention, the operating status of the working equipment displayed on the liquid crystal panel
Information, or failure or abnormality of work equipment
The color of the light emitted from the backlight changes according to the emergency information shown, and the color for displaying the steady information and the emergency information is different. When emergency information is displayed on the screen, the information can be surely visually distinguished from the steady information. Moreover, the display of regular information and the display of emergency information are large.
Both information is easy to see
Become

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151]

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a liquid crystal display device suitable for the present invention.

FIG. 2 is a circuit diagram showing a simplified backlight switching circuit in the embodiment.

FIG. 3A is a perspective view showing another embodiment of the liquid crystal display device suitable for the present invention, and FIG. 3B is XX in FIG.
Sectional drawing which showed the line cross section.

FIG. 4 is a perspective view showing the case in this embodiment from behind.

FIGS. 5A and 5B are cross-sectional views showing another embodiment of a liquid crystal display device suitable for the present invention.

FIG. 6 is a cross-sectional view illustrating a configuration of a liquid crystal display device when a comparative evaluation of luminance is performed.

FIG. 7 is a perspective view showing one embodiment of a liquid crystal display device suitable for the present invention.

FIG. 8 is a sectional view showing a section taken along line XX in FIG. 7;

FIG. 9 is a sectional view showing another embodiment of the liquid crystal display device suitable for the present invention.

FIG. 10 is a sectional view showing an embodiment of a liquid crystal display device suitable for the present invention.

FIG. 11 is a sectional view showing an embodiment of a liquid crystal display device suitable for the present invention.

FIG. 12 is a schematic diagram showing one embodiment of a liquid crystal display device suitable for the present invention.

FIG. 13 is a configuration diagram showing one embodiment of a liquid crystal display device suitable for the present invention.

FIG. 14 is a flowchart showing a processing procedure for turning on a red backlight.

FIG. 15 is a time chart showing the timing of switching from a white backlight to a red backlight.

16A is a perspective view showing a conventional liquid crystal display device, and FIG. 16B is a perspective view showing a cross section taken along line XX in FIG.

FIG. 17 is a perspective view showing a conventional liquid crystal display device provided with an LED for displaying an operation mode.

FIG. 18 is an explanatory diagram for explaining a dark effect unique to a colored backlight.

[Explanation of symbols] 1 LCD panel 2 First backlight 3 Second backlight 4 Light guide plate 5 Backlight switching circuit 6 Reflector 10 LCD panel 11 Body 12 First backlight 13 Second backlight 14 Light guide plate 15 cases 20 LCD panel 21 First backlight 22 Second backlight 23 Light guide plate 24 Printed circuit board 25 Diffusing plate 26 Reflective film 27 Reflector A, B Position where the backlight is arranged 30 Body case 30a Front panel 31 LCD display window 32 transparent window 33 LCD panel 34 Light guide plate 35 First backlight 36 Second backlight 37 Printed Wiring Board 38 Plastic body 40 body case 41 LCD display window 42 LCD panel 43 Diffuser 44 Light guide plate 44a Incident surface 45 Reflector 46 Backlight 47 Backlight lighting circuit 48 LCD shutter 48a, 48b Half shutter surface 49 Shutter control circuit 50 red filter 51 drums 51a through hole 52 Drum control circuit 53 Red filter 54 Green Filter 60 liquid crystal display 61 Patlite control interface 62 Patlite 70 White backlight 71 Red backlight 75 White light switch 76 Red light switch 77 Switch control unit 80 body 81 LCD panel 82 Backlight 83 Light guide plate 90 Body case 90a Front panel 91 LCD panel 92 LED

Continuation of the front page (72) Inventor Nobuhisa Yabuno 10 Omron Co., Ltd., Hanazono Todocho, Ukyo-ku, Kyoto-shi (56) References JP-A-62-205388 (JP, A) JP-A-2-238439 (JP) JP-A-4-106896 (JP, A) JP-A-3-296018 (JP, A) JP-A-4-102888 (JP, A) Japanese Utility Model 2-62516 (JP, U) Japanese Utility Model 1-57796 (JP, U) Japanese Utility Model Application 59-156224 (JP, U) Japanese Utility Model Application 62-173722 (JP, U) Japanese Utility Model Application 62-37541 (JP, U) (58) Field surveyed (Int. Cl. ^7, DB name) G02F 1/13357

Claims (1)

(57) [Claims] (1)LCD panel, Arranged behind the liquid crystal panel and incident on the entrance surface
A light guide plate for guiding light to the back of the liquid crystal panel, A first backlight light source that emits light of a stationary color;
Second backlight that emits light of a color different from the stationary color
A light source and a light guide plate,
Light from the first and second backlight sources is incident on the
A backlight light source device, Command signals from work equipment installed at the work site such as a factory
Based on the operating conditions of the work equipment, etc.
The first backlight light source is turned on,
If you want to display emergency information indicating device failure or
Back light to switch on the backlight light source
Light switching means, A first backlight light source and a second backlight light source;
That is, the liquid crystal panel is irradiated with light that increases the brightness.
Position the backlight light source close to the LCD panel
Backlight that irradiates light that reduces brightness
By arranging the light source far from the LCD panel,
Brightness difference between steady information and emergency information displayed on LCD panel
Was made smaller Liquid crystal display device characterized by the following:
Place.