JP3289145B2 - 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 when 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.
One backlight light source (hereinafter simply referred to as a backlight) 82 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.

To solve this problem, it is conceivable to display the stationary message and the urgent message in different colors. However, even if display in another color is technically possible, space and cost are limited in a compact liquid crystal display device, so that display of any color is easy to see and furthermore, identification is easy. Displaying in another easy-to-use color has not been easy.

A backlight 82 is a liquid crystal panel 81.
Because it is fixed inside the main body 80 attached with
When the backlight 82 is replaced, there is a problem that the main body 80 and the liquid crystal panel 81 must be also replaced.

Further, in the conventional liquid crystal display device having 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.

On the other hand, in order to solve the above problem, it is conceivable to use a colored light irradiating backlight made of a cold cathode fluorescent lamp of red or the like. However, this colored backlight is turned on in a dark place such as inside the apparatus body. In this case, there is a problem that it is difficult to light due to a dark effect peculiar to a colored backlight.

Here, as shown in FIG. 18, the dark effect means that the longer the elapsed time in a dark place, the longer the time required to turn on the colored backlight.

In view of the above, the present invention has been made in view of the above problems, and has excellent visibility in displaying an urgent 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.

[0014]

According to a first aspect of the present invention, there is provided a liquid crystal panel, comprising: a liquid crystal panel disposed behind the liquid crystal panel; A light guide plate, and a white backlight light source disposed facing the light incident surface of the light guide plate, and disposed between the light incident surface of the light guide plate and the white backlight light source, transmitting light of a color other than the steady color. A color filter to be provided, disposed between the light incident surface of the light guide plate and the white backlight light source, and irradiating the light of the white backlight light source through the color filter to be incident on the light incident surface of the light guide plate, or Displays a shutter that switches whether the light enters the light-incident surface of the light guide plate without passing through the filter, and displays steady-state information indicating the operating status of the work equipment based on command signals from work equipment installed at the work site such as a factory. If you When the light is incident on the light incident surface of the light guide plate without passing through the color filter, and when emergency information indicating a failure or abnormality of the work equipment is displayed, the light is transmitted through the color filter and incident on the light incident surface of the light guide plate. And a shutter control means for switching a shutter.

According to a second aspect of the present invention, there is provided a liquid crystal panel.
Placed behind the LCD panel and incident on the entrance surface.
Light guide plate for guiding light to the back of the liquid crystal panel, and the light guide plate
A white backlight source facing the entrance surface of the
Arranged between the entrance surface of the light guide plate and the white backlight light source
And a color filter that transmits light of colors other than
The position at which the light emitted from the white backlight source reaches the light guide plate
Optical path switching control means for changing
Optical path disconnection based on command signals from work equipment installed at the site
The operating status of the work equipment is indicated by the control of the replacement control means.
When displaying steady information, do not pass through the above color filter
Switch to the first optical path to indicate failure or abnormality of work equipment
When displaying emergency information, the
It is characterized by switching to two optical paths. According to the present invention, when stationary information is displayed on the liquid crystal panel,
A partial surface of the shutter facing the color filter by the shutter control unit or the optical path switching control unit is defined as a light blocking surface, and the other partial surface is defined as a light passing surface. As a result, the light of the backlight enters the light guide plate without passing through the color filter, and steady information is displayed on the liquid crystal panel in the color of the light of the backlight as it is.

When an instruction to display emergency information is displayed during the steady information display, the shutter control means sets a part of the shutter facing the color filter as a light transmitting surface and another part as a light blocking surface. I do.

Then, the light of the backlight passes through the color filter, becomes an emergency color, and enters the light guide plate. As a result, the emergency information is displayed on the liquid crystal panel in an emergency color different from the steady color.

[0018]

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

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 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 a change in the liquid crystal state, and forms a contour 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 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 light emitted from the first and second backlights 2 and 3 is directly incident on the side surface 4a of the light guide plate 4, but is reflected on the back surface 4b 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 showing the backlight switching circuit 5 in this embodiment.
As shown in this figure, the backlight switching circuit 5 includes first and second backlights 2 connected in parallel to an AC power supply 7,
3 comprises a first switch 5a and a second switch 5b for turning ON / OFF separately. The first switch 5a is opened and closed based on a command signal A output from an external device (not shown). 1 backlight 2 is O
N / OFF, and the second backlight 3 is turned ON / OFF by opening and 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.

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 case. Becomes

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 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 message can be displayed on the liquid crystal panel 1 from a distance where the message cannot be read. It is possible to visually recognize that the emergency message is displayed.

Further, 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.

FIG. 3A is a perspective view showing another embodiment of the liquid crystal display device suitable for the present invention, and FIG.
FIG. 2 is a cross-sectional view showing a cross section taken along line XX in FIG.

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 that the first and the second liquid crystal panels are provided inside the main body 11. Second backlight 12, 13
And the first and second backlights 12, 1
Light guide plate 14 for guiding light emitted from 3 to liquid crystal panel 10
Are also arranged inside the main body 11.

Further, the first and second backlights 1
The units 2 and 13 are housed in a case 15 that can be attached to and detached from the main body 11, and a backlight switching circuit (not shown) is also built in the main body 11.

Next, the configuration 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 above embodiment. The description is omitted because it is the same as.

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 provided 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 formed in an elongated shape having 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 above 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, the 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 to the first embodiment,
The second 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. It is possible to easily replace only the backlight separately from the main body 11.

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, in the liquid crystal display device, first and second backlights 21 and 22 and a light guide plate 23 are arranged behind a liquid crystal panel 20 in substantially the same manner as in the above-described embodiment.
Further, a printed circuit board 2 forming a backlight switching circuit
4 is also disposed behind the liquid crystal panel 20, but in FIG. 4A, the first backlight 21 that emits white light is located on one side surface 23 a of the light guide plate 23 and the liquid crystal panel 2.
0, and a second backlight 22 for irradiating red light is provided on one side surface 23a of the light guide plate 23, like the first backlight 21; Located far from the

Further, in FIG. 2B, 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. 5A and 5B, the liquid crystal panel 20 has a second backlight 22 that irradiates red light more than a 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 the liquid crystal display device when a comparative evaluation of luminance is performed.
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 for irradiating white light to A and a second backlight 22 for 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.

[0056]

[Table 1]

Next, a second backlight 22 for irradiating red light to A and a first backlight 21 for irradiating white light to B are arranged, and both backlights 21 and 22 are turned on.
Assuming that the case of / OFF was the experiment (2), the following luminance measurement results were obtained on the diffusion plate 25.

[0058]

[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 luminance difference is smaller when the second backlight 22 that irradiates red light is located farther from the diffusion plate 25 than the first backlight that irradiates white light.

As a result of the comparative evaluation based on the above experiments (1) and (2), according to the present embodiment, a position farther than the first backlight 21 with respect to the liquid crystal panel 20 as in the experiment (1). Backlight 22 for irradiating red light to the
Are arranged, the luminance difference between white light and red light is reduced, and both red and white colors can be displayed brightly on the liquid crystal panel 20.

Next, another embodiment of the liquid crystal display device suitable for the present invention will be described.

The description of the same configuration and operation as those of the above-described embodiment will be omitted.

FIG. 7 is a perspective view showing another embodiment of the liquid crystal display device suitable for the present invention, 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 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 through the transmission window 32. However, when the first backlight 35 is ON, the work equipment and the like are not used. 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 displaying an emergency message on the liquid crystal panel 33, the first and second backlights 35, 36
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.

Thus, according to this embodiment, the first and second backlights 35, 35 are used to display the operation mode of the work equipment or the like without using LEDs as in the prior art.
Since light according to the operation mode can be emitted from the transmission window 32 using the light of 36, the power consumption is reduced as compared with the case where an LED is provided for displaying the operation mode, and the light of the transmission window 32 is Because it is captured as light from a light source,
The light in the transmission window 32 can be viewed from a distance.

FIG. 9 is a sectional view showing another embodiment. The liquid crystal display device according to this embodiment scatters light to the transmission window 32 shown in FIGS. 7 and 8. A scatterer plastic body 38 is provided.

The plastic body 38 scatters light in various directions by 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. Light emitted from the transmission window 32 can be visually recognized even from the lateral direction of the transmission window 32, that is, from the side of the front panel 30a of the main body case 30.

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 side light 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 lit by the backlight lighting circuit 47 and radiates 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 48 b serving as the light passage surface and passes through the red filter 50 without passing through the red filter 50 to the half of the incident surface 44 a of the light guide plate 44. Incident.

Then, the light incident on the half of the incident surface 44a 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. You.

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.

Thus, 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 only one backlight lighting circuit 47 for controlling ON / OFF of the backlight 46 is provided. The device can be made smaller and space-saving 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 a light blocking surface and a light passing surface at a 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.

Next, 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 is omitted.

In the liquid crystal display device shown in this figure, a tubular drum (light
Road switching control means) 51 is provided.
Reference numeral 1 denotes an elongated through-hole 51a which is rotatable about the backlight 46 and which is provided on a part of the peripheral surface of the drum 51 so as to allow the white light of the backlight 46 to reach half of the incident surface 44a of the light guide plate 44. Is open.

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 displaying a steady message 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 generated. Is displayed.

Therefore, according to this embodiment, two colors can be displayed by one backlight 46 as in the above-described embodiment, and only one backlight lighting circuit 47 is provided. It is possible to reduce the size and space of the apparatus as compared with the two-color display using the backlight.

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-described embodiment, and the liquid crystal display device 60 has a rotation indicator light as an alarm via a rotation indicator light control interface 61. (Patlite (trademark))
62 are 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 transmits an emergency message from a working device (not shown) or the like. The display color switching signal is received, and the display color switching signal is also received by the rotary indicator control interface 61.

When the rotation indicator light control interface 61 receives the display color switching signal and activates the rotation indicator light 62, the rotation indicator light 62 is activated while the liquid crystal display device 60 is displaying an emergency message with red light. Will be done.

Therefore, according to this embodiment, since the rotation indicator light 62 operates in addition to the display of the emergency message by the red light, the worker working away from the liquid crystal display device 60 may be in an emergency. An occurrence can be signaled.

FIG. 13 is a configuration 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 the liquid crystal display device of FIG. 1, and a white backlight 70 for irradiating white light and a red light. A red backlight 71 for irradiating is provided, and white and red lighting circuits 72, illuminating 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, 71
Is disposed close to a dark place in the apparatus main body.

The switch control section 77 switches ON / OFF of the white and red lighting switches 75 and 76 based on a command signal. The white and red backlights 70 and 76 are switched in accordance with the switching operation of the switch control section 77. 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 (S
(Step 110 “NO”), the state of STEP 100 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).

Thus, 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 the 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 to turn off the white backlight 70 (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 it is necessary to set the white and red backlights 70 and 71 to the simultaneous lighting state. 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.

If there is an instruction to turn on red light (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 passed since the white backlight 70 was turned on, the switch control unit 77 performs the processing after STEP 200, thereby eliminating the dark / dark effect when the red backlight 71 is turned on, as described above.

Therefore, according to the present embodiment, when the red backlight 71 is turned on, the simultaneous lighting state of the red backlight 71 and the white backlight 70 is continued for a predetermined time, and the red backlight 71 at the time of lighting is maintained. Since the periphery is brightened by the white light of the white backlight 70 and the so-called dark effect is eliminated, the red backlight 71 can be quickly turned on, and the display color of the liquid crystal panel is smoothly switched from white to red. .

Next, another embodiment of the present invention will be described.

This embodiment is substantially the same as the above-described embodiment, except that an illumination light source such as an LED illuminating the periphery of the backlight 71 is provided separately from the white backlight 70 shown in FIG. The switch control unit 77 turns on / off the lighting switch of the irradiation light source in addition to the white and red lighting switches 75 and 76.

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 directed to a liquid crystal display device capable of displaying two colors, three colors can be obtained by increasing the number of backlights and color filters, or by dividing the liquid crystal shutter into three or more shutter surfaces. The above display is also possible.

[0125]

As is apparent from the above description, according to the present invention, the steady information indicating the operation status of the working equipment displayed on the liquid crystal panel, or the emergency information indicating the failure or abnormality of the working equipment, etc. The color of the light emitted from the backlight changes according to the color of the display, and the color used to display the steady information and the emergency information is different. If information is displayed,
The information can be surely visually distinguished from the regular information.

Further, since the color for displaying the information is changed by passing the light of the backlight through the color filter by the switching of the shutter or the optical path switching control means , or by bypassing the color filter, one type of light is used. Since the color backlight is kept on and the color filter is fixed, the color filter is less susceptible to damage and has a longer life than the movable filter.

[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 according to the embodiment;

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

FIG. 4 is a perspective view showing the case according to the 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 an 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 a 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 view showing an 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]

 Reference Signs List 1 liquid crystal panel 2 first backlight 3 second backlight 4 light guide plate 5 backlight switching circuit 6 reflector 10 liquid crystal panel 11 main body 12 first backlight 13 second backlight 14 light guide plate 15 case 20 liquid crystal 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 backlight is arranged 30 Body case 30a Front panel 31 Liquid crystal display window 32 Transmission Window 33 Liquid crystal panel 34 Light guide plate 35 First backlight 36 Second backlight 37 Printed wiring board 38 Plastic body 40 Main case 41 Liquid crystal display window 42 Liquid crystal panel 43 Diffusion plate 44 Light guide plate 44a Incident surface 45 Reflector 46 Back Light 47 Backlight lighting circuit Reference Signs List 8 liquid crystal shutters 48a, 48b shutter half half 49 shutter control circuit 50 red filter 51 drum 51a through hole 52 drum control circuit 53 red filter 54 green filter 60 liquid crystal display device 61 patrol light interface 62 patrol light 70 white backlight 71 red backlight 75 White lighting switch 76 Red lighting switch 77 Switch control unit 80 Main body 81 Liquid crystal panel 82 Backlight 83 Light guide plate 90 Main body case 90a Front panel 91 Liquid crystal panel 92 LED

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // F21Y 103: 00 F21Y 103: 00 (72) Inventor Nobuhisa Yabuno 801 Fudogawa-cho, Horikawa-Higashi-iri, Shiokoji-shi, Shimogyo-ku, Kyoto OMRON Stock In-company (56) References JP-A-4-186315 (JP, A) JP-A-62-205388 (JP, A) JP-A-2-238439 (JP, A) ) Actually Opened 2-62516 (JP, U) Actually Opened 1-57796 (JP, U) Actually Opened Showa 59-156224 (JP, U) Actually Opened Showa 62-173722 (JP, U) Actually Opened Showa 62- 37541 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/3357 F21V 8/00 601 G09F 9/00 336 G09F 9/00 337

Claims (2)

(57) [Claims] 1. A liquid crystal panel, a light guide plate disposed behind the liquid crystal panel and guiding light incident on an incident surface to a rear surface of the liquid crystal panel, and a white backlight disposed opposite the incident surface of the light guide plate. A light source, a color filter disposed between the incident surface of the light guide plate and the white backlight light source, and transmitting light of a color other than the steady color; and between the incident surface of the light guide plate and the white backlight light source. A shutter which is arranged and switches between irradiating light of a white backlight light source through the color filter to be incident on the incident surface of the light guide plate, and switching between irradiating the incident light of the light guide plate without transmitting the color filter; Based on the command signal from the work equipment installed at the work site, etc., when displaying the steady information indicating the operation status of the work equipment, etc., the light is incident on the incident surface of the light guide plate without passing through the color filter. A liquid crystal display comprising: shutter control means for switching the shutter so as to transmit the color filter and enter the light incident surface of the light guide plate when displaying emergency information indicating a failure or abnormality of the device. apparatus. 2. A liquid crystal 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, White backlight placed opposite the light-entering surface of the light guide plate
Light source, Arranged between the incident surface of the light guide plate and the white backlight light source
A color filter that transmits light of a color other than the stationary color, The position where the light emitted from the white backlight source reaches the light guide plate
Optical path switching control means for changing the Command signals from work equipment installed at the work site such as a factory
Control of the work equipment by the control of the optical path switching control means based on the
Use the above color filter to display steady information
Switch to the first optical path that does not pass through the
If you want to display emergency information that indicates
To switch to the second optical path that passes through the
Characteristic liquid crystal display device.