JPH1115402A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device easy to see information displayed on a liquid crystal display and saving a mounting space to an equipment also. SOLUTION: In this display device 1, the surface of the liquid crystal display 4 of an STN(supertwisted nematic) system making a diagonal size of a display screen 7 to 8 inches, selecting the number of pixels to 640×480 dots and setting a dot pitch in 0.2 to 0.25 mm is covered by a touch panel 5. Then, the touch panel 5 is fixed to the liquid crystal display 4 by a frame body 6, and a thin type fitting base part 7 attachably/detachably inserted/fixed into a recessed part formed on the equipment is formed on this frame body 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using a liquid crystal display for monitoring an operation state of a device such as a production facility or a plant.

[0002]

2. Description of the Related Art A display device using a liquid crystal display is attached to equipment used in a production facility of a factory that produces consumer goods, industrial products, and the like, and equipment used in a chemical plant or the like. Displaying information formed by combining graphics etc. on the screen, the operator switches the display contents of the screen as appropriate using the touch switches arranged on the screen, and monitors the operation state of equipment such as production equipment and plants Is widely practiced.

The above-mentioned display device for monitoring the operation state of equipment such as production facilities and various plants is not provided as a screen of a personal computer, but is used by being directly attached to the surface of the equipment to be operated. I have. Therefore, there is a special feature that the screen display contents are switched by operating the touch switches arranged on the screen, instead of switching the display contents of the screen by operating the keyboard or mouse unlike a personal computer. It is required that the contents displayed on the screen be read accurately.

In such a display device, the size of the display screen and the number of pixels of the liquid crystal display are set in consideration of the operability of the operator, the visibility of the display screen, and the space for mounting the apparatus. In the related art, it is considered that the display device is installed at a position close to the operator's work site, so that the operator can easily access the display screen of the display device, and the size of the screen is not so necessary. And
In consideration of the mounting space, the display screen of the display device has a small size of about 5 inches diagonally.

FIG. 5 is a schematic perspective view showing an example of use of a conventional display device. In the figure, reference numeral 1 denotes a display device using a liquid crystal display, and 2 denotes a device used in a production factory or various plants to which the display device 1 is attached. As a liquid crystal display used in the display device 1, a display screen having a small size with a diagonal dimension of about 5 inches and a number of pixels of 320 × 240 dots is used.

As described above, when the size of the display screen is small, the amount of information displayed on the screen is limited. Therefore, when it is necessary to display a large amount of information, the display of the screen is frequently switched and the necessary information is changed. Information is displayed. When the amount of information to be displayed on the screen is large, it is conceivable to display the necessary information on two screens by arranging the liquid crystal display on the device 2, but the space for attaching the display device 1 to the device 2 increases. However, there arises a problem that the size of the device 2 increases and the cost increases accordingly.

[0007] When the size of the display screen is small, the amount of information to be displayed is small and it is inconvenient. Therefore, a display device with an enlarged display screen has been developed. FIG. 6 is a schematic perspective view showing another example of use of the conventional display device. In this example, the liquid crystal display of the display device 1 attached to the device 2 has a large display screen size of about 10 to 12 inches diagonally, and has a number of pixels of 640 × 480 dots. . When a display screen having a large size is employed, the amount of information displayed on the screen increases.

[0008]

In the configuration using a small liquid crystal display as shown in FIG. 5, the size of the display screen is small and the number of pixels is small, so that it is difficult for the operator to read the information displayed on the screen, and the screen display is difficult. Has to be changed frequently, and the operation becomes complicated.

Further, in the configuration using a large liquid crystal display as shown in FIG. 6, the liquid crystal display is expensive and the space required for mounting the display device on the equipment increases, resulting in an increase in the size of the equipment. There was a problem.

The present invention has been made in view of the foregoing problems, and has as its object to provide a display device configured so that an operator can accurately read displayed information without increasing a space for mounting the device.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a display device having a display screen with a diagonal dimension of 7 to 8 inches, a pixel count of 640.times.480 dots, and a dot pitch of 640.times.480 dots. From 0.2 to 0.25 in each direction of the matrix
mm, the surface of the STN type liquid crystal display is covered with a touch panel, the touch panel and the liquid crystal display are fixed with a frame, and the frame is removably inserted and fixed in a recess formed in the device. This is achieved by forming a thin mounting base.

According to the above features of the present invention, it is possible to obtain a display device having a configuration in which information displayed on a liquid crystal display is easy for an operator to read, and which does not require a large installation space in equipment.

[0013]

Embodiments of the present invention will be described below with reference to FIG. FIG. 1 is a schematic perspective view showing a display device according to the present invention, partially cut away, and FIG.
It is sectional drawing of the AA direction of arrow. In the figure, 1 is a display device, 4 is a liquid crystal display, 5 is a transparent touch panel disposed over the surface of the liquid crystal display 4, 6 is a frame for fixing the liquid crystal display 4 and the touch panel 5, and 7 is a device surface. A mounting base which is removably inserted into the recess to be formed, on which a power supply connection portion of the liquid crystal display 4 and a control circuit such as a CPU are mounted. The mounting base is integrally molded with the frame 6 or mechanically formed by screws or the like. It is connected to. The power supply connection portion of the liquid crystal display 4 and the control circuit such as the CPU are mounted on the mounting base 7 as described above, but the depth is set so that the device on which the display device is installed can be inserted even if the device is small. The thickness is about 50 mm and formed thin.

The frame 6 uses a conventional display screen on which a small liquid crystal display having a diagonal dimension of about 5 inches is mounted, so that the space for mounting the display device 1 on the apparatus does not increase. So you are considering. As described above, by increasing the screen ratio of the liquid crystal display in the frame 6 having the same size as before, the screen is easy to see and the operability is improved. Furthermore, when the display device 1 is attached to the device, the frame 6 is exposed on the surface of the device. However, in consideration of aesthetics and workability, in order not to take up extra space around the device. The frame 6 is set as thin as possible so that the portion protruding from the device surface is as small as possible.

The liquid crystal display 4 has a super twisted nematic having a large twist angle (Super Twisted N).
e., e.g., e.e., STN). For this reason, even when the device to which the display device 1 is attached is installed in a dark place such as a factory, the operator can easily read the information displayed on the screen, and mistakenly recognizes the operation state of the device or the like and performs the operation. Errors can be prevented. Note that the STN type liquid crystal display uses a thin film transistor (Thin FilmTrans).
The contrast is lower than that of a liquid crystal display of the (istor, TFT) type, but there is an advantage that it can be obtained at low cost.

The display screen has a medium size of 7 to 8 inches in diagonal size which has not been adopted in a display device, and the number of pixels is the same as that of a conventional large liquid crystal display. 640 x 480 dots, which was adopted only for the display device that was used.

Further, the number of pixels is limited only to a conventional monitor using a large-sized liquid crystal display.
40 × 480 dots are selected, but the dot pitch of the display screen is set to about 0.3 mm in the row and column directions used in the conventional large-sized liquid crystal display. From 0.2 to 0.2
By changing the setting to 5 mm, the contrast of the display screen is further increased to make it easier to read information. In a color liquid crystal display, the dot pitch in the column direction is (0.2 to 0.25 mm) / 3,
To form RGB dots.

As described above, in the present invention, the display device 1
The liquid crystal display 4 used in the above is a medium-sized display screen having a diagonal size of 7 to 8 inches in the STN mode, and the number of pixels is selected to be 640 × 480 dots.
Since the dot pitch of the display screen is set to 0.2 to 0.25 mm, the operator can read the displayed information accurately. It is also possible to adjust the backlight to make the screen even brighter. In addition,
The information displayed on the screen is configured to be compatible with either the monochrome system or the color system.

The display device 1 is removed from the device for maintenance and inspected. Also, since the display device 1 is attached to a device such as a production facility or a variety of plants, the display device 1 is affected by vibrations or the environment such as ambient temperature and humidity is severe. Therefore, if a failure occurs, replacement is necessary. Therefore, the mounting base 7 is inserted into a recess formed on the surface of the device, and is detachably fixed with screws or pins. In addition, a sheet or a cover may be attached to the surface of the touch panel 5 to protect the display device 1 from dust and the like.

FIG. 3 is a block diagram showing an example of a control system of such a display device. In the figure, a bus line 11 is connected to a central processing unit (hereinafter abbreviated as CPU) 10, and a ROM 12, a RAM 13, and an input / output port I / 014 are connected to the bus line 11. In addition, the bus line 11
Is connected to a display controller 15, an image memory 16 is connected to the display controller 15, and the liquid crystal display 4 is connected via an appropriate interface.

The display controller 15 is an image memory 1 composed of a DRAM or the like based on information from the CPU 10.
The necessary data is read out from the image data stored in the memory 6 and predetermined information such as characters and figures is displayed on the liquid crystal display 4. Layouts of characters and graphics corresponding to the special arrangements of various devices and equipment such as factories and plants in which the display device 1 is installed, routes of medium distribution of liquids and gases, and configurations of control systems. Is set on the screen of the liquid crystal display 4.

Further, as for the monitoring of the operating state of a large number of devices arranged in the production facility and the monitoring of the continuous process of a chemical plant or the like, all information cannot be displayed on the screen at one time. The necessary information amount is divided into a plurality of pieces in advance, and the divided information is configured to be continuously displayed on the screen, and the operator sequentially switches the display screen to perform monitoring. As described above, the image data stored in the image memory 16 has various contents set in accordance with the specifications of the user.

Further, by connecting to an external computer via the bus line 11 provided in the control system of the display device 1, an operator touches the surface of the touch panel 5 while transmitting and receiving data to and from the CPU 12, thereby providing a liquid crystal display. Change the layout of the display screen of the display 4 as appropriate,
It is also possible to make color drawing a favorite.

FIG. 4 is a front view showing an example of a screen displayed on the liquid crystal display 4 of the display device 1 used in a chemical plant. In the example shown in the figure, the operation mode of the three tanks can be switched between manual and automatic, and the operation state of each tank can be monitored by operating the touch switches 8 and 9 on the touch panel. In the example of this display screen, piping between three tanks, installation positions of valves and tanks, liquid flow, and the like are displayed.

[0025]

The liquid crystal display used in the display device of the present invention employs a medium-sized display screen having a diagonal size of 7 to 8 inches, so that the conventional diagonal size is about 5 inches. The amount of information displayed on the screen is larger than that using a small-sized liquid crystal display. In addition, the number of pixels is increased compared to conventional small-sized liquid crystal displays, and the contrast of the screen is also increased, so that the operator can read the displayed information accurately and prevent erroneous recognition or erroneous operation of the operation state of equipment etc. can do.

In addition, the conventional diagonal dimension is 10 to 12
Since a large-sized liquid crystal display of about an inch requires less space for installing a display device, there is no need to increase the size of a device to which the display device is attached. As a result, the cost for installing the display device can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a configuration of a display device according to a preferred embodiment of the present invention, partially cut away.

FIG. 2 is a sectional view taken in the direction of arrows AA in FIG.

FIG. 3 is a block diagram showing a configuration of a control system of a display device applied to the present invention.

FIG. 4 is a front view showing an example of a screen displayed on a liquid crystal display by the display device of the present invention.

FIG. 5 is a schematic perspective view showing attachment of a conventional display device to a device.

FIG. 6 is a schematic perspective view showing attachment of another conventional display device to a device.

[Explanation of symbols]

 Reference Signs List 1 display device 2 device 4 liquid crystal display 5 touch panel 6 frame 7 mounting base 8, 9 touch switch 10 CPU 11 bus line 12 ROM 13 RAM 14 input / output port 15 display controller 16 image memory

Claims (1)

[Claims] 1. The display screen has a diagonal size of 7 to 8 inches, a pixel number of 640 × 480 dots, and a dot pitch of 0.2 to 0.25 in each direction of the matrix.
mm, the surface of the STN type liquid crystal display is covered with a touch panel, the touch panel and the liquid crystal display are fixed with a frame, and the frame is removably inserted and fixed in a recess formed in the device. A display device comprising a thin mounting base.