JPS61262791A - Display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a display device that displays signal levels, etc., and in particular, the present invention relates to a display device that displays signal levels, etc. This relates to something that enables selective lighting.

[Conventional technology]

Conventionally, a display device suitable for a level meter or the like that uses a light emitting diode (LED) to display a signal level as desired has been used, but the inventor proposed a display device as shown in Fig. 3. I did□.

This display device connects a plurality of LEDs in series and parallel, and allows drive current to flow selectively to any LED, thereby reducing current consumption. That is, in this display device, as shown in FIG. 3, a plurality of LED'la, 2b, 2c, and 2d whose driving current is set in one direction are connected in series, and the driving current is set to each of the LED's 2a to 2d. LEDs 2e, 2f, 2g, and 2h whose directions are set in opposite directions are connected in parallel, and these LEDs 2a to 2d, 2e to 2h
A bidirectional driver 4 that outputs a drive current or flows a drive current to the most end side of the series-parallel circuit according to switching.
．． 6 are installed respectively, and each LED 2a to 2d, 2e to
A one-way driver 8 is installed to draw in or draw out a drive current from the connection point of 2h.

[Problem that the invention seeks to solve]

Therefore, in such a display device, by switching the direction of the drive current with the bidirectional driver 4.6, two
Channel display is possible, and it is advantageous in that power consumption is reduced by connecting multiple LEDs in series. It is not possible to select one element and turn it on.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a display device that can select and display one element in the middle of a series circuit of LEDs.

[Means for solving problems]

The display device of the present invention connects in series a plurality of display elements (LEDs 2a to 2d) each having a driving current set in one direction, and each display element having a plurality of display elements (LEDs 2a to 2d) each having a driving current set in the opposite direction. A bidirectional driver (108 ~10
e) is installed.

[For production]

Display elements have current directionality, so display elements in the forward direction are placed in a state where they can be driven with respect to the drive current applied from the bidirectional driver, while display elements in the opposite direction are prohibited from being driven. Ru. Then, when a drive current is caused to flow from the bidirectional driver located at the end of the series-parallel circuit of display elements and between the display elements, the display element selected by the drive current lights up.

When a plurality of display elements are turned on, the display can be selectively maintained by selecting one of the display elements and flowing current into or out of the display element.

In addition to LEDs, the display element may be an incandescent lamp whose direction of current flow is set by a diode.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the display device of the present invention.

As shown in FIG. 1, LEDs 2a, 2b, 2c, and 2d are connected in series as a plurality of display elements with drive current set in one direction, and each LED 2a to 2d has a drive current set in the opposite direction. LED2e as the set display element,
2f, 2g, and 2h are connected in parallel.

Bidirectional drivers 10a, 10b, 10c, 110d, and 10e that supply a drive current or flow out a drive current according to switching to the ends of the series/parallel circuits of these LEDs 2a to 2d, 2e to 2h and to each connection. is installed.

Therefore, in such a display device, for example, when current is applied from the bidirectional driver 10a and current is applied from each of the bidirectional drivers 10b to 10e, the LEDs 2a to 2
d are sequentially driven. For example, bidirectional driver 10c
When current flows out, both LEDs 2a and 2b light up. In this case, the drive current for the LEDs 28 to 2h is in the opposite direction, so the drive thereof is blocked.

Also, when current is applied from the bidirectional driver 10e and current is applied from each of the bidirectional drivers 10d to 10a, the LE
D2 h to 2e can be lit. in this case,
The LEDs 2a to 2d are driven in the opposite direction, so their driving is blocked, as described above.

Then, when current is applied from the bidirectional driver 10e and current is applied from the bidirectional driver 10c, the LED 2g,
Both 2h lights up, but in this case, bidirectional driver 1
0b, and the bidirectional driver 10a.
When the current is started to flow out, LED2f turns off and the L
ED2e lights up.

Here, it goes without saying that the output point potential of the bidirectional driver 10b is set so as not to be higher than the output point potential of the bidirectional driver 10c.

Further, for example, when current is applied from the bidirectional driver 10b and current is applied from the bidirectional driver 10c, the LE
D2b can be turned on.

In this way, in this display device, the direction in which the drive current flows is selected, and the bidirectional drivers 10a to 10e selectively operate the LEDs 2a to 2d.

2e to 2h can be selected and lit in stages, and any one of the end LEDs 2a, 2d, 2e12h or the intermediate LEDs 2b, 2c, 2f, and 2g can be selected and lit. .

FIG. 2 shows a specific example of the circuit configuration of the display device of the present invention.

Each bidirectional driver 10a to 10e includes a transistor 12
．． 14.16 and a resistor 18.20, and a switching input terminal 2 is connected to the base of the transistor 12.16, respectively.
2a and 22b are provided. That is, in each bidirectional driver 10a to 10e, transistor 12.1
4 and resistors 18 and 20 constitute a drive circuit for flowing current into the LED side, and transistor 16 constitutes a drive circuit for flowing current from the LED side.

Therefore, such bidirectional drivers 10a to lOe
In this case, when the switching input terminals 22a and 22b are held at H (high) potential, the transistor 2 becomes conductive, the transistor 14 becomes non-conductive, and the transistor 16 becomes conductive, and in this case, the driving current is in the flow mode. becomes. Also,
When the switching input terminals 22a and 22b are held at L (low) potential, the transistor 12 becomes non-conductive, the transistor 14 becomes conductive, and the transistor 16 becomes non-conductive, thereby switching the drive current to the flow-out mode. becomes.

For this reason, by selectively switching the current mode of each bidirectional driver 10a'-10e, as explained in the above embodiment, the drive current can be selectively caused to flow in the direction of the drive current and to any part. , a single LED or multiple LEDs can be selectively illuminated.

Although an LED is used as a display element in the embodiment, a similar display can be realized by using an incandescent lamp with a diode added thereto to provide directionality.

〔Effect of the invention〕

As explained above, according to the present invention, since each display element is connected in series and parallel, the current consumption and power consumption can be reduced, and the part through which the drive current flows can be arbitrarily selected. The LED can be turned on and, for example, peak hold display can be realized in level display.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the display device of the present invention, FIG. 2 is a circuit diagram showing a specific example of the circuit configuration of the display device of the present invention, and FIG. 3 is a block diagram showing a conventional display device. It is. 2a to 2h...LEDs as display elements. 10a to 10e...bidirectional drivers. Figure 3

Claims (2)

[Claims] (1) A plurality of display elements whose drive current is set in one direction are connected in series, and display elements whose drive current is set in the opposite direction are connected in parallel to each display element. 1. A display device comprising a bidirectional driver that causes current to flow into or out from the display element side from the endmost side of a series-parallel circuit and the connection between each display element. (2) The display device according to claim 1, wherein the display element is constituted by a light emitting diode or an incandescent lamp provided with directionality using a diode.