JP3304521B2 - Moving visual 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 moving visual display device for allowing a person moving on a train or the like to visually recognize an arbitrary image composed of a large number of pixels with a small number of light emitting elements. In particular, the present invention relates to a configuration of a power supply unit of the device unit installed along a track of a train or the like.

[0002]

2. Description of the Related Art JP-A-2-67589, JP-A-4-4-1
2277, JP-A-4-210702, JP-A-4-2
As disclosed in, for example, Japanese Patent Application Laid-Open No. 08-9993, a linear display (light-emitting cell array) in which high-brightness light-emitting diodes (LEDs) and the like are arranged one-dimensionally is used, and the observer moves with respect to the display. The following moving visual display system has been put to practical use in which an image of a surface is visually recognized by an afterimage effect of the eyes.

A linear display is installed vertically on the wall of a subway tunnel, and image data in a bitmap format is sequentially read out from a memory by a display control device in units of lines, and an LED array of the linear display is connected to each line. It is configured to drive to blink according to data. The display output is performed when the train passes the installation location of the linear display. At that time, the display speed (line data switching cycle) is adjusted according to the speed of the train.

[0004] When a person on a train looks at the inside and outside of the car vaguely, the linear display moves at high speed just outside the window. At that time, the LED array of the linear display is blinking according to the image data. Since the person in the car does not follow this linear display (because it cannot), the linear display is scanned by the observer in a direction orthogonal to the longitudinal direction, and the image is observed by the afterimage effect. The image of the surface is visually recognized by the person.

An image of one screen is displayed by one linear display, but a plurality of linear displays are installed at appropriate intervals along the track of the subway, and the timing of the image output operation is appropriately adjusted. , A plurality of screens can be sequentially viewed as moving images.

[0006] Such a moving visual display system has the following features.
It is composed of a number of display units with one linear display as one unit, and a host computer that controls all the units. Each unit and the host computer are connected with a control cable and laid along each unit. The connected power cable and each unit are connected.

[0007] The case of each of the above units includes an LED array as a linear display, a driving circuit for the LED array,
A memory for temporarily storing image data to be displayed, an interface with a host computer, a microprocessor for supervising control and data processing in each unit such as management and output of image data, and its accompanying circuits, An AC / DC converter (switching power supply) that obtains DC power of each unit in the unit from a power input is mounted.

[0008]

When the above-mentioned movable visual display system is implemented in a subway tunnel or the like,
In many cases, a new power cable connected to a large-capacity AC power supply must be laid to supply power to each unit in the tunnel, and the work of installing each unit at the site inside the tunnel is very troublesome. There was a problem.
In addition, there is a problem that the AC / DC converter built in each unit is large, so that the thickness of the unit case cannot be reduced too much. The distance between the wall surface of the tunnel and the side surface of the passing vehicle is not so large, so that the thickness of the unit installed on the wall surface of the tunnel should be small.

Both of the above two problems are caused by the fact that the power consumption during the display operation of each unit is considerably large.

Although the power consumption of a logic circuit centering on a microprocessor built in each unit is very small, a large number of LEDs constituting a linear display are blinked simultaneously according to image data during a display operation. The power consumption is quite large. Even if the driving current of each LED is small, 128 or 256 L
The ED must be prepared for driving the ED at the same time, so that the AC can be supplied to supply the necessary current.
The DC / DC converter must have a considerably large capacity.
As a result, compared to other components built into the unit,
The size of the C / DC converter becomes conspicuous.

A large number of units constituting the system perform a display operation at the same time when a train passes through the installation area. As described above, although the power consumption during the display operation of each unit is large, since many units operate simultaneously, the power consumption of the entire system becomes extremely large. Therefore, in many cases, it is not possible to take in the power of each unit from the existing AC power supply cable laid in the tunnel, and a power supply cable having a sufficient capacity must be newly laid in the tunnel. The work of newly laying an AC power cable in a required place in an existing tunnel is very troublesome, and the difference from using an AC power cable already laid for a power source for lighting or the like is extremely large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to reduce the capacity and size of an AC / DC converter incorporated in each unit and to connect each unit. It is an object of the present invention to provide a mobile visual display device in which the AC power supply equipment to be used has a small capacity.

[0013]

SUMMARY OF THE INVENTION Accordingly, the present invention focuses on the fact that, in this type of system, the power consumption in a short time when a train or the like passes is large, but the idle period in which the power consumption is very small is very long. In a mobile visual display device in which the light emitting cell array, image data output means, timing control means, and the like are mounted in one unit case, a power connector for connecting an external AC power cable; An AC / DC converter for converting an AC power applied to the power connector into a predetermined DC, a secondary battery, and a charging control circuit for charging the secondary battery with a DC output of the AC / DC converter; A power source for a light source in the light emitting cell array from the secondary battery;
The power supply of the logic circuit unit in the image data output means and the timing control means is obtained from the output of the DC converter.

[0014]

When a relatively fast moving object such as a train passes through the installation area of the device, a display operation is performed by the light emitting cell array. The operation time is not so long, and the operation pause time until the next observation moving body approaches is usually much longer. According to the configuration of the present invention, the rechargeable battery is charged over a sufficiently long time during the operation suspension period, and during a short-time display operation, a large current is taken out from the rechargeable battery and the light source of the light emitting cell array is turned off. Driven. Since the charging current when the operation is stopped may be considerably smaller than the discharge current of the secondary battery during the display operation, the capacity of the AC / DC converter can be reduced, and accordingly, the AC input power is also reduced.

[0015]

FIG. 1 shows an external appearance and a mounted state of a movable visual display device according to an embodiment of the present invention. The movable visual display device of the present invention basically displays one screen.
It consists of units, but usually a plurality of units are arranged at appropriate intervals along the track of the train. FIG. 1 shows two units in a display system including a large number of units.

The components of one display unit are mounted on a unit case 1 having an elongated shape. The unit case 1 is vertically mounted on a wall of a subway tunnel by a bracket 2. On the front of the unit case 1, there is a vertically long transparent window, in which, for example, 128 LEDs
LED array 3 is disposed outward. In addition, a photoelectric train sensor 4 for detecting passage of a train is provided on the lower front part of the case 1 toward the outside. A number of these display units, mounted on the tunnel wall along the subway track, are connected immorally by a commercial AC power cable 5 and
It is connected in an immortal manner by a signal cable 6 to be described later.

FIG. 2 shows a schematic configuration of a circuit system built in one display unit. In this circuit system, overall timing control and main data processing are performed by a one-chip microcomputer 7.

In FIG. 2, bit-mapped image data (supplied from a host computer as described later) is stored in a memory 9. At the time of display operation, the memory 9 is accessed by the address counter 8, image data is sequentially read out, and the serial data is transferred to the line buffer 11 by the serial-parallel conversion circuit 10 by a predetermined number of bits. The display driver 12 turns on or off individual LED elements of the LED array 3 in accordance with one line of image data in the buffer 11.

The above-described timing control of the display operation is performed by the microcomputer 7 in accordance with the passing situation of the vehicle. The microcomputer 7 includes the train sensor 4 of the unit.
And the detection signal of the train sensor of the unit installed in the preceding stage in the traveling direction of the train is input. The speed information of the passing train and the passing timing of the unit are determined based on these detection signals, and the above-described display operation timing and output speed are appropriately controlled.

The microcomputer 7 of each unit is connected to a host computer (not shown) via a communication interface 13 and a signal cable 6.
It also controls (writes) image data provided from the host computer in the memory 9.

Next, the configuration of the power supply system of the display device unit, which is a main part of the present invention, will be described in detail.

According to the present invention, an existing AC power supply facility installed in a subway tunnel can be used. A power connector 14 is provided on a circuit board built in each unit case 1, and an AC power cable 5 is connected to the power connector 14 in an immortal manner. An AC / DC converter 15 (so-called switching power supply) is mounted on a circuit board in the case 1, and an AC power supply input applied to the power supply connector 14 is converted into a stable DC of a predetermined voltage. The DC output of the AC / DC converter 15 is supplied as operating power for the microcomputer 7, the memory 9 and its peripheral circuits, the train sensor 4, and the logic circuit unit such as the communication interface 13 (the power supply line is not shown). ).

A nickel-cadmium secondary battery 17, a capacitor 18 having a relatively large capacity in parallel with the battery 17, and an output of the AC / DC converter 15 are connected to a circuit board in the case 1. A charging control circuit 16 for charging is mounted. The circuit is connected so that the terminal voltages of the secondary battery 17 and the capacitor 18 serve as a drive power source for the LED array 3.

The charging control circuit 16 detects the charging voltage of the secondary battery 17 and transmits it to the microcomputer 7, and the microcomputer 7 controls the charging control circuit 16 appropriately in accordance with the charging voltage information, and suspends the above-described display operation. During the period, the charging current is appropriately controlled so as to sufficiently charge the secondary battery 17 in preparation for the next display operation.

When the display operation is performed as described above when the train passes through the installation location of the unit, a large number of LEs
The light emission drive current of the LED array 3, which is a group of D elements, is covered by the discharge of the secondary battery 17 and the capacitor 18. Then, during the suspension period until the next display operation, the secondary battery 17 and the capacitor 18 are charged over a sufficiently long time. Therefore, the light emission drive current during the display operation may be considerably large, and the charging current of the secondary battery 17 may be considerably small. As a result, the input current from the AC power cable 5 to the AC / DC converter 15 is small.

Note that the light emitting cell array is not limited to the LED array 3 of the embodiment, and other devices such as a combination of a liquid crystal shutter array and a backlight, a combination of a PLZT shutter array and a backlight, and a fluorescent display tube are used. In this case, the present invention can be similarly applied.

[0027]

As described above in detail, according to the present invention, even if the power consumption during the display operation of each display unit is considerably large, most of the power is not covered by the discharge of the secondary battery. In addition, since the secondary battery is slowly charged during the operation suspension period that is sufficiently long to prepare for the next display operation, the current supplied from the AC power supply to the unit does not increase. Therefore, when implementing the above-mentioned moving visual display system in a subway tunnel or the like,
The AC power supply equipment for supplying power to a large number of display device units does not need to have a large capacity, and it is possible to use an existing AC power supply cable laid in the tunnel. As a result, installation work of this type of display system is greatly simplified, and the system price including installation can be greatly reduced. Also, the AC / DC converter in the unit can be of a small capacity, so that the converter can be downsized, which is very effective in reducing the thickness of the entire device unit.

[Brief description of the drawings]

FIG. 1 is a front view showing an appearance and an installed state of a movable visual display unit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a circuit system built in the display device unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Unit case 3 LED array 4 Train sensor 5 AC power cable 6 Signal cable 7 Microcomputer 9 Image data memory 12 Display driver 14 Power supply connector 15 AC / DC converter 16 Charge control circuit 17 Secondary battery 18 Capacitor

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G09G 3/00

Claims (1)

(57) [Claims] A light emitting cell array in which a large number of light emitting cells are arranged in a predetermined layout; and image data output means for supplying image data to be displayed in a predetermined amount to the light emitting cell array in order and driving the display. And a timing control means for operating the image data output means at an appropriate speed in response to the passing information of the observation moving body, and the timing control means is mounted on one unit case, and the vicinity of the apparatus is the moving body. When the observer moves, the image of the light emitting cell array driven to be displayed by the image data output means is scanned on the retina of the observer, whereby the intended image is visually recognized by the observer due to the afterimage effect. A power connector for connecting an external AC power cable, and a power supply applied to the power connector. An AC / DC converter for converting an AC power supply into a predetermined DC, a secondary battery, and a charge control circuit for charging the secondary battery with a DC output of the AC / DC converter are mounted on the unit case; A secondary battery is a power source of a light source in the light emitting cell array, and an output of the AC / DC converter is a power source of a logic circuit unit in the image data output unit and the timing control unit. Visual display device.