JPS587422Y2 - Display status reading device for magnetic reversal type display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display state reading device for a magnetic reversal type display device.

As schematically shown in FIG. 1 of the accompanying drawings, a magnetic reversal type display device is generally mounted using a stator pin 2 provided so as to pass through a plate 1, and a rotating display device with a color surface and a black surface on the front and back sides. It is equipped with disk 3.

The stator pin 2 is provided with a drive winding 4 having a set input terminal S1, a reset input terminal Hb, and a common terminal C.

By flowing a drive current to the set input terminal S, the polarity of the magnetic poles 2A and 2B of the stator pin 2 can be reversed, and the rotating disk 3 can be rotated so that its colored surface is displayed.

In addition, by flowing a drive current to the reset input terminal R, the polarity of the magnetic poles 2A and 2B of the stator pin 2 is returned to the original state, and the rotating disk 3 is rotated so that its black side is displayed, returning to its original state. Various methods and devices have recently been proposed for reading out the display state of the rotating disk 3 in such a magnetic reversal type display device.

Among them, as shown in FIG.
There are some that apply

By applying a read current to the reset input terminal R, the direction of the residual magnetization of the stator pin 2, that is, the output voltage induced in the detection coil 6 and appearing between the lead wires 6A according to the display state of the rotating disk 3 can be changed. The display state can be read by the size.

Conventionally, in such a readout device, a certain threshold value is set to determine the magnitude of the output voltage of the detection coil.
A method that recognizes the display status is adopted.

This type of system poses no problem when a display device like the one shown in Figure 1 is used as a single unit, but when a large number of display devices like the one shown in Figure 1 are used as display elements to produce a single display. In the case of a graphic display panel used as a system, there are the following problems.

That is, when a large number of display elements are used, variations in characteristics among each display element, such as (1) changes in the magnetic property buttons of the stator pin and rotating disk and their magnetization states; (2) detection coils; There are considerable variations in the winding position and winding method, as well as variations in the current taken out (3), and the output voltage of the detection coil for each display element varies considerably.

Therefore, the display state of each display element is determined by setting a fixed threshold value for all display elements and comparing this with the output voltage of the detection coil of each display element.
A display element having characteristics considerably different from average characteristics is likely to cause reading errors considerably.

The purpose of the present invention is to provide a display state reading device for a magnetic reversal type display device that eliminates the drawbacks of the conventional devices as described above and that can reliably identify the display state regardless of variations in the characteristics of display elements. The goal is to provide the following.

The above-mentioned object of the present invention can be distantly achieved by setting an appropriate threshold value for each display element instead of setting a fixed threshold value for all display elements.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, particularly FIGS. 2, 3, and 4, with reference to embodiments of the invention.

FIG. 2 schematically shows an embodiment of the identification circuit of the readout device according to the invention.

This identification circuit uses a peak hold amplifier and is coupled to the detection coil 6 of the display device shown in FIG.

In a reading device coupled with such an identification circuit, detection of the display state is performed in a total of three sequences: two sequences for reading and one sequence for rewriting.

1. In the first sequence, at the same time, a read drive current is applied to the reset input terminal R of the display element of FIG. 1, and at the same time, the identification circuit of FIG.
Add pulse signal to T1.

At this time, the output voltage generated in the detection coil 6 is passed through the preamplifier 10 to the capacitor C of the peak hold section 100.
Added to 1.

The peak hold unit 100 includes an operational amplifier 2A and a capacitor C1, and outputs and holds the peak value of the voltage applied through the preamplifier 10.

The output voltage of the peak hold section 100 is applied to the + input terminal of the differential amplifier 20C of the threshold setting section 200.

A voltage determined by a potentiometer VRI is applied to one input terminal of the differential amplifier 20C.

Therefore, the output of the differential amplifier 20C is the voltage determined by the potentiometer V-Rt and the peak hold section 1
This is the voltage difference from the output voltage of 00.

This differential voltage is level-adjusted by a potentiometer VR2 and applied to the +input terminal of the comparator 40.

In the second sequence, a read drive current is applied once again to the reset input terminal R of the display element of FIG.
Add pulse signal to ET2.

At this time, the output voltage generated in the detection coil 6 is applied to the capacitor C2 coupled to the operational amplifier 20B through the preamplifier 10, and its voltage value is held, and the comparator 4
0 is given to one input terminal.

The purpose of the threshold setting unit 200 is to adjust the voltage applied to the + input terminal of the comparator 40 in order to make the voltage applied to one input terminal of the comparator 40 an appropriate threshold for display state determination. It is to be.

Assuming that there is no threshold setting unit 200, the voltage applied to the + input terminal C of the comparator 40 is the curve vCi□ of FIG. 4A when the rotating disk 3 is displaying a color surface.
When the rotating disk 3 is displaying a black surface, the curve becomes as shown in the curve VO2 in FIG. 4A.

In either case, the voltage applied to one input terminal of comparator 40 is as shown by curve vD in FIG. 4C.

A threshold setting section 200 is provided to set voltages Vo□ and vc2.
The voltage vR determined by the potentiometer VRI
(see Figure 4C) and adjust the level appropriately with potentiometer VR2.
The voltages applied to the + input terminal C of 0 are shown in Figure 4B.
By setting voltages such as 1iIvc Ver' and V.

21).

That is, voltage vD, voltage Vc1'b and voltage VO2'
The display state of the rotating disk can be reliably determined based on the output of the comparator 40 that compares the values.

Following the readout sequence of the display state, as a third sequence, a pulse signal is given for the manual reset of the identification circuit shown in Fig. 2, for the ET heliset), and the drive current for rewriting is applied to set the display element shown in Fig. 1. It is added to the input terminal S or the reset input terminal R depending on its original display state to complete - reading operations.

A timing chart of each signal for the read operation as described above is shown in FIG.

FIG. 3A shows the read drive current pulse A1 applied in the first sequence, the read drive current pulse A2z- applied in the second sequence, and the rewrite drive current pulse A3 applied in the third sequence. It shows the series.

FIG. 3B shows a voltage waveform B1 generated at the output point A of the preamplifier 10 of the identification circuit of FIG. 2 in the first sequence, a voltage waveform B2 generated at the same output point A in the second sequence, and the same voltage waveform B2 in the third sequence. Voltage waveform B3 generated at output point A
shows the series.

FIG. 3C shows the sequence of pulse signals applied to the set input 5ET1 of the identification circuit of FIG. 2 in a first sequence.

The third diagram shows the sequence of pulse signals applied to the set input 5ET2 of the identification circuit of FIG. 2 in the second sequence.

FIG. 3E shows a series of reset pulse signals applied to the reset manual RESET of the identification circuit of FIG. 2 in the third sequence.

FIG. 3F shows the series of voltages occurring at the output point B of the comparator 40 of the identification circuit of FIG. 2 between the second and third sequences.

As described above, the readout device of the present invention creates a display state determination threshold level according to the unique characteristics of each magnetic reversal type display device, and uses the threshold level to determine the display state of the display device. Therefore, even if there are variations in the characteristics of each display device, the display state of each display device can be reliably and accurately read out.

[Brief explanation of the drawing]

FIG. 1 of the accompanying drawings is a diagram schematically showing an example of a magnetic reversal type display device provided with a reading means, FIG. 2 is a circuit diagram showing an embodiment of the identification circuit of the reading device according to the present invention, and FIG. 3A to F are timing charts of each signal of the read operation for the circuit of FIG. It is a figure which illustrates. 1... Mounting on plate, 2... Stator pin, 2A, 2B
... Magnetic pole, 3... Rotating disk, 4... Drive winding, 6... Detection coil, 10... Preamplifier, 5ET
1.5ET2...Set input, RESET...Reset input, C1°C2...Capacitor, 20A, 20
B... Arithmetic amplifier, 20C... Percussion amplifier, VR1y
VR2...Potentiometer, 40...Comparator.

Claims (1)

[Scope of utility model registration request] In a magnetic reversal type display device equipped with a stator pin having a rotating disk for display and a drive winding that drives the rotating disk in reverse, a detection coil provided on the stator pin and a detection coil provided on the drive winding in a first sequence a first peak hold section that holds the peak value of the output voltage from the detection coil when a readout drive current pulse is applied to the drive winding in a second sequence; a second peak hold section that holds the peak value of the output voltage from the detection coil; and a differential amplifier that receives the output voltage from the first peak hold section and a predetermined voltage and outputs a differential voltage therebetween. The vessel and
It is characterized by comprising a comparator that compares the output voltage from the second peak hold section and the differential voltage from the differential amplifier and outputs a signal instructing the display state of the rotating disk. display status reading device.