JP2010243568A - Non-contact drive type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-contact drive type display device 1 that is easily manufactured and maintained and is configured at low cost. <P>SOLUTION: The non-contact drive type display device 1 includes: a display substrate 2 where a display circuit 21 including a serial resonance circuit 25 having a prescribed resonance frequency and a display element 23 is formed; a drive substrate 3 where a driving circuit 31 for output of driving signals which drive the display circuit 21 and a drive side inductor 3L for output of the driving signals generated by the driving circuit 31 are formed; and a holding member 50 for holding the display substrate 2 and the drive substrate 3. The display substrate 2 and the drive substrate 3 are made to face each other separately and the driving signals are transmitted from the driving circuit 31 to the display circuit 21 by electromagnetic induction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a non-contact drive type display device that transmits a drive signal from a drive circuit to a display circuit by electromagnetic induction.

  Conventionally, various types of displays have been researched and developed. These displays can be broadly classified into two. On the other hand, for example, display elements such as PDP (Plasma Display Panel), organic EL (Electro Luminescence), inorganic EL, LED (Light Emitting Diode), FED (Field Emission Display), and CRT (Cathode Ray Tube) emit light. What to do. On the other hand, for example, display elements such as LCD (Liquid Crystal Display), DMD (Digital Mirror Device), and electronic paper do not emit light, and another light source is required.

  Here, television displays using LCDs, PDPs, and the like have increased in screen size, and large displays of, for example, 100 inches or more have also been developed (see, for example, Non-Patent Document 1). In addition, a display using an organic EL is mounted on, for example, a mobile phone terminal or a small mobile device (see, for example, Non-Patent Document 2). In addition, a display using an LED is widely used as an electric bulletin board that displays various information (for example, train time) outdoors such as a station. Furthermore, the display using inorganic EL is widely used, for example, as a sheet-like cheap surface light source.

  These displays mainly have a structure in which a display element including a light emitter and an optical shutter and a drive circuit for driving the display element are stacked to form a single substrate. In addition, these displays are configured by two substrates, a substrate having a display element and a substrate having a drive circuit, and a structure in which the display element and the drive circuit are physically connected by wiring (for example, Patent Document 1). In the invention described in Patent Document 1, a substrate having a display circuit having a light emitting layer TFT and a substrate having a drive circuit are manufactured separately, and both circuits are connected by electrodes and driven.

JP 2008-281986 A

R. Murai et al .: Proc. IDW07, 2007 pp.783-786 M.Kobayashi et al.:Proc.IDW07,2007 pp.221-224

  However, in the structure in which the display element and the drive circuit as described above are stacked on a single substrate and the structure in which two substrates are physically connected by wiring, the following problems occur. When only one of the display element and the drive circuit fails or is damaged, it is impossible to separate them, so it is necessary to repair or replace the entire substrate, which makes maintenance difficult and increases maintenance costs. .

  In addition, in the structure in which the display element and the drive circuit are stacked on one substrate, in the manufacturing process, only the display element or the drive circuit has a defect, and the entire substrate is treated as a defective product. It is difficult to improve the manufacturing yield. Further, when an organic EL or LCD is used as a display element, it is necessary to form a driving TFT near the display element, which causes a problem that the manufacturing process becomes complicated and the manufacturing cost increases. In particular, when a high heat treatment such as vapor deposition of electrodes on the substrate is included, the manufacturing process becomes more complicated in order to prevent adverse effects on the display element.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a non-contact drive type display device that is easy to manufacture and maintain and can be configured at low cost.

  In order to solve the above-described problems, a non-contact drive display device according to the first invention of the present application includes a display substrate on which a display circuit including a resonance circuit having a predetermined resonance frequency and a display element is formed, and the display circuit. A non-contact drive type display device that separates and faces a drive substrate on which a drive circuit that outputs a drive signal to be driven is formed and transmits the drive signal from the drive circuit to the display circuit by electromagnetic induction, The drive substrate includes a drive-side inductor that outputs a drive signal generated by the drive circuit, and the display circuit includes the resonance circuit that has a frequency of the drive signal input from the drive-side inductor. When the frequency coincides with the resonance frequency, the drive signal is output to the display element.

  According to this configuration, the non-contact drive display device can transmit a drive signal by electromagnetic induction between the non-contact drive circuit and the display circuit. As a result, the non-contact drive type display device can manufacture the display substrate and the drive substrate separately, so that there is almost no adverse effect on the display element due to the high heat treatment in the drive substrate manufacturing process. In addition, since the non-contact display device can be easily separated from the display substrate and the drive substrate even after completion, only one of the display substrate and the drive substrate can be replaced or repaired.

  Further, in the non-contact drive display device according to the second invention of the present application, the resonance circuit is a series resonance circuit in which a display-side inductor and a capacitor to which the drive signal is input from the drive-side inductor are connected in series. The display circuit is characterized in that the display element and the series resonant circuit are connected in series.

  According to such a configuration, when the frequency of the drive signal coincides with the resonance frequency of the series resonance circuit, the non-contact drive display device is configured such that the impedance of the series resonance circuit is substantially zero, so that the drive signal is the series resonance circuit. Is output to the display element.

  Further, in the non-contact drive display device according to the third invention of the present application, the resonance circuit is a parallel resonance circuit in which a display-side inductor and a capacitor are connected in parallel, and the display circuit is driven from the drive-side inductor to the drive. An input inductor to which a signal is input is further provided, and the display element and the parallel resonant circuit are connected in series to the input inductor.

  According to such a configuration, when the frequency of the drive signal matches the resonance frequency of the parallel resonance circuit, the non-contact drive display device has an infinite impedance of the parallel resonance circuit, so that the drive signal is parallel to the parallel resonance circuit. Without being transmitted to the display element.

  In the non-contact drive display device according to the fourth invention of the present application, the display-side inductor includes a core material having a relative magnetic permeability of 10 or more and 10,000 or less, and the capacitor has a thickness of 0.01 micrometers or more and 5 or more. A dielectric having a thickness of micrometer or less and a relative dielectric constant of 10 to 5000 is provided.

  According to this configuration, the non-contact drive display device can reduce the size of the display-side inductor and the capacitor. In this case, for example, iron, cobalt, or nickel can be used as the core material. As the dielectric, for example, strontium titanate, barium titanate, or lead zirconate titanate (PZT) can be used.

  The non-contact drive type display device according to the fifth invention of the present application is characterized by comprising a holding member for holding the display substrate and the drive substrate at a predetermined interval. According to such a configuration, the non-contact drive display device can hold the display substrate and the drive substrate at intervals at which electromagnetic induction occurs.

According to the present invention, the following excellent effects can be obtained.
According to the first aspect of the present invention, the display substrate and the drive substrate are manufactured separately, and the display substrate and the drive substrate can be easily separated even after completion. Thus, according to the first invention of the present application, there is almost no adverse effect on the display element due to the high heat treatment in the drive substrate manufacturing process, and only one of the display substrate and the drive substrate can be replaced or repaired. Easy maintenance and low cost.

  According to the second and third aspects of the present invention, since the display element emits light only when the frequency of the drive signal matches the resonance frequency of the resonance circuit, it is possible to control (select) which display element emits light.

  According to the fourth aspect of the present invention, since the display-side inductor and the capacitor can be reduced in size, the non-contact drive display device can be made high definition.

  According to the fifth aspect of the present invention, since the display substrate and the drive substrate can be held at intervals where electromagnetic induction occurs, a drive signal can be transmitted from the drive circuit to the display circuit.

1 is a schematic view of a non-contact drive display device according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram for explaining an operation principle in the non-contact drive display device of FIG. 1. It is explanatory drawing explaining the 1st example of the holding member in 1st Embodiment of this invention, (a) is a perspective view of a non-contact drive type display apparatus, (b) is A of a non-contact drive type display apparatus. It is -A 'sectional drawing. It is explanatory drawing explaining the 2nd example of the holding member in 1st Embodiment of this invention. It is explanatory drawing explaining an operation principle in the non-contact drive type display apparatus which concerns on 2nd Embodiment of this invention. It is explanatory drawing explaining Example 1 of this invention. In the resonant circuit in Example 2 of this invention, it is a graph which shows the relationship between an inductance when a capacity | capacitance is made constant, and a resonant frequency.

First Embodiment: Series Resonant Circuit)
[Configuration of non-contact drive display device]

  Each embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In each embodiment, the same member is denoted by the same reference numeral, and the description thereof is omitted.

  Hereinafter, the configuration of the non-contact drive display device according to the first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the non-contact drive display device 1 includes a display substrate 2 and a drive substrate 3 that are spaced apart from each other. Further, the non-contact drive display device 1 holds the display substrate 2 and the drive substrate 3 at a constant interval by a holding member (see FIGS. 3 and 4) described later. Details of the holding member will be described later.

  The display substrate 2 is formed with a display circuit 21 to be described later. The display substrate 2 is a general substrate such as a printed substrate, a glass substrate, or a silicon substrate. Here, the display substrate 2 has a predetermined number of display circuits 21 formed in a matrix in the vertical and horizontal directions. The number of display circuits 21 and the arrangement on the display substrate 2 are not limited to this.

  Each of the display circuits 21 is a closed circuit in which a display element 23 and a series resonance circuit 25 are connected in series as shown in FIG. Here, the display element 23 may be an electro-optical element such as an LED, an organic EL, an inorganic EL, an LCD, an electronic paper, an FED, or a DMD that modulates light according to an electric signal (drive signal). Further, the display element 23 does not emit light with the power of the drive signal when the resonance frequency of the series resonance circuit 25 to be described later does not match the frequency of the drive signal, and the resonance frequency of the series resonance circuit 25 and the frequency of the drive signal. It is preferable to emit light with the power of the drive signal when the two coincide. In other words, the display element 23 has a light emission start voltage that exceeds the voltage of the drive signal when the resonance frequency of the series resonance circuit 25 and the frequency of the drive signal do not match, and is driven by the resonance frequency of the series resonance circuit 25. It is preferably less than the voltage of the drive signal when the frequency of the signal matches.

  Here, when the display circuit 21 is formed by stacking, the film thickness of the display circuit 21 is preferably 10 nm or more and 1 mm or less. Further, the film thickness is more preferably 1 μm or less because the non-contact drive type display device 1 can be made high-definition by laminating by a fine processing technique such as photolithography.

  Further, for example, when high definition is not required such as an electric bulletin board outside a station or the like, the display circuit 21 is a display element such as a commercially available LED and a package of an inductor and a capacitor as will be described later. It can also be formed using.

  The series resonance circuit 25 includes a display-side inductor 25L and a capacitor 25C connected in series, and has a predetermined resonance frequency. The display-side inductor 25L constitutes the series resonance circuit 25 and inputs a drive signal from the drive-side inductor 3L described later to the display circuit 21 by electromagnetic induction. The display-side inductor 25L is formed of a conductive material, and is preferably a material having a low resistance value such as Al, Cu, Au, Ag, Cr.

  The drive substrate 3 of FIG. 1 includes a drive circuit 31 and a drive-side inductor 3L corresponding to the display circuit 21. The drive substrate 3 is a general substrate such as a printed substrate, a glass substrate, or a silicon substrate. Here, a plurality of drive substrates 3 in which a predetermined number of drive-side inductors 3L are connected in series in the horizontal direction are arranged in units of rows. Further, the drive circuit 3 is connected to each of the leading drive-side inductors 3L located on the drive circuit 31 side (right side in FIG. 1) and the drive circuit 31. The drive substrate 3 is connected to the last drive side inductor 3L (left side in FIG. 1) and the grounded resistor 3R.

  The drive circuit 31 is connected to a signal source 40 that generates a drive signal for driving each display circuit 21, and outputs this drive signal to the drive-side inductor 3 </ b> L corresponding to each display circuit 21. Here, as shown in FIG. 1, since the drive-side inductor 3L is arranged in units of rows in the horizontal direction, the signal source 40 sequentially generates drive signals in units of rows. Further, the drive circuit 31 outputs a drive signal to the row including the drive-side inductor 3L corresponding to the drive signal. Then, when the drive signal is input, the drive-side inductor 3L outputs this drive signal to the display-side inductor 25L by electromagnetic induction.

  The connection method between the drive circuit 31 and the drive-side inductor 3L is not performed in units of rows as shown in FIG. 1, and can be arbitrarily set according to conditions such as the frequency band of the drive signal. Here, the drive substrate 3 may directly connect all the drive-side inductors 3 </ b> L and the drive circuit 31. Further, the drive substrate 3 may connect all the drive-side inductors 3L to each other, and may connect any one drive-side inductor 3L and the drive circuit 31 at only one place.

  The drive circuit 31 and the drive-side inductor 3L may be laminated by a fine processing technique such as photolithography as in the display circuit 21. The drive-side inductor 3L may be the same as the display-side inductor 25L. Furthermore, the display circuit 21 and the drive-side inductor 3L correspond one-on-one, but they may correspond one-to-one (where N is an integer of 2 or more).

<Operation principle of non-contact drive type display device>
Hereinafter, the operation principle of the non-contact drive display device 1 will be described with reference to FIG. 2 (see FIG. 1 as appropriate). 2A to 2C, the upper side corresponds to the display substrate 2 and the lower side corresponds to the drive substrate 3. 2A to 2C, for the sake of explanation, one display circuit 21, the corresponding drive-side inductor 3L and the signal source 4 are illustrated, and the drive circuit 31 is not illustrated. .

  As shown in FIG. 2A, when the drive signal from the signal source 40 is input, the drive-side inductor 3L generates a magnetic field B corresponding to the drive signal. The display-side inductor 25L generates an electromotive force (drive signal) according to the magnetic field B. That is, the non-contact drive display device 1 transmits a drive signal between the drive-side inductor 3L and the display-side inductor 25L that are not in contact with each other by electromagnetic induction.

  As shown in FIG. 2B, when the resonance frequency of the series resonance circuit 25 matches the frequency of the drive signal, the series resonance circuit 25 resonates. At this time, since the impedance of the series resonance circuit 25 becomes substantially zero, the power of the electromotive force (drive signal) E becomes maximum, and the display element 23 emits light according to the drive signal.

  On the other hand, as shown in FIG. 2C, when the resonance frequency of the series resonance circuit 25 and the frequency of the drive signal do not match, the series resonance circuit 25 does not resonate. At this time, the electromotive force (drive signal) E hardly flows through the series resonance circuit 25, and the display element 23 does not emit light. That is, the non-contact drive display device 1 can control (select) the display element 23 that emits light according to the relationship between the frequency of the drive signal and the resonance frequency of the series resonance circuit 25. Therefore, in the non-contact drive display device 1, it is preferable that the series resonance circuits 25 have different resonance frequencies.

<Holding member: first example>
Hereinafter, a first example of the holding member 50 of the non-contact drive display device 1 will be described with reference to FIG. 3 (see FIG. 1 as appropriate). In FIG. 3, the holding member 50 is the housing of the non-contact drive display device 1.

  As shown in FIG. 3A, the holding member 50 has an opening that exposes the display surface 2 a on which the display circuit is formed on the display substrate 2, and is slightly longer than the display substrate 2 and the drive substrate 3. It is a cuboid shape. Further, as shown in FIG. 3B, the holding member 50 is formed with an edge 51 protruding on the display surface 2 a of the display substrate 2 so that the display substrate 2 is not detached. The holding member 50 is formed with a convex portion 53 protruding on the inner side surface, holds the display substrate 2 and the drive substrate 3 at a constant distance, and fixes the display substrate 2 and the drive substrate 3 inside the housing. Further, the holding member 50 can open any one side surface, and can detach the display substrate 2 and the drive substrate 3.

<Holding member: second example>
Hereinafter, a second example of the holding member 50 of the non-contact drive display device 1 will be described with reference to FIG. 4 (see FIG. 1 as appropriate). In FIG. 4, the display substrate 2 and the drive substrate 3 respectively have through holes at four corners where circuits and the like are not formed. The holding member 50 is inserted into each through hole, and holds the distance between the display substrate 2 and the drive substrate 3 constant. Although the holding member 50 is a cylindrical member, a combination of bolts and nuts may be used to securely hold and fix the display substrate 2 and the drive substrate 3.

<Specific example of manufacturing method>
Hereinafter, referring back to FIG. 1, a specific example of a method for manufacturing the non-contact drive display device 1 will be briefly described. In this example, the non-contact drive display device 1 used as an outdoor LED display is manufactured. First, the non-contact drive display device 1 prints a wiring pattern on the surface of a display substrate 2 such as a printed substrate. And the non-contact drive type display apparatus 1 arrange | positions LED, a capacitor | condenser, and an inductor in the predetermined position on a wiring pattern in the display board 2 with which the wiring pattern was printed.

  Further, the non-contact drive display device 1 prints a wiring pattern on the surface of a drive substrate 3 such as a printed circuit board. Then, the non-contact drive display device 1 places an inductor at a predetermined position on the wiring pattern on the driving substrate 3 on which the wiring pattern is printed. As the drive circuit 31, for example, a programmable IC (Integrated Circuit) can be used. Thereafter, the non-contact drive display device 1 forms the display substrate 2 and the drive substrate 3 and then attaches both the substrates to the holding member. As described above, the non-contact drive type display device 1 does not need to electrically connect the display substrate 2 and the drive substrate 3 using electrodes or the like. Therefore, both substrates can be manufactured separately, and only one of the substrates can be manufactured. Can be easily replaced or repaired.

  Note that the non-contact drive display device 1 can also manufacture the display substrate 2 and the drive substrate 3 by a fine processing technique such as general photolithography. At this time, the non-contact drive type display device 1 is not limited to the planar circuit as shown in FIG. 1, and may be a laminated circuit.

  As described above, the non-contact drive display device 1 can transmit a drive signal by electromagnetic induction between the drive circuit 31 and the display circuit 21 that are not in contact with each other. As a result, the non-contact drive display device 1 can manufacture the display substrate 2 and the drive substrate 3 separately, so that there is almost no adverse effect on the display element 23 due to the high heat treatment in the drive substrate manufacturing process. In addition, since the non-contact drive display device 1 can be easily separated from the display substrate 2 and the drive substrate 3 even after completion, only one of the display substrate 2 and the drive substrate 3 can be replaced or repaired. . Further, the non-contact drive type display device 1 does not require a driving TFT. Thus, the non-contact drive display device 1 is easy to manufacture and maintain, and is low in cost.

  In the non-contact drive display device 1, the drive-side inductor 3 </ b> L includes not only the series resonance circuit 25 but also a function of inputting a drive signal by electromagnetic induction. As a result, the non-contact drive display device 1 can reduce the number of components and the cost.

(Second embodiment: parallel resonant circuit)
[Configuration of non-contact drive display device]
Hereinafter, the configuration of the non-contact drive display device according to the second embodiment of the present invention will be mainly described with reference to FIG. 5 in terms of differences from the first embodiment (see FIG. 1 as appropriate). The non-contact drive type display device 1B according to the second embodiment is largely different in that the display circuit 21 includes an input inductor 27 and a parallel resonance circuit 29 instead of the series resonance circuit 25.

  As shown in FIG. 5A, the display circuit 21 includes a display element 23, an input inductor 27, and a parallel resonance circuit 29. The input inductor 27 receives a drive signal from the drive-side inductor 3L. The parallel resonant circuit 29 is a circuit in which a display-side inductor 29L and a capacitor 29C are connected in parallel. The display element 23 and the parallel resonance circuit 29 are connected to the installed resistor on the opposite side of the input inductor 27. That is, the display circuit 21 is a circuit in which the display element 23, the display-side inductor 29L, and the capacitor 29C are connected in series to the input inductor 27.

  The display-side inductor 29L and the capacitor 29C are the same as the display-side inductor 25L and the capacitor 25C in FIG. In addition, the driving substrate in the second embodiment is the same as that shown in FIG. Furthermore, the holding member in the second embodiment is the same as that shown in FIGS.

<Operation principle of non-contact drive type display device>
Hereinafter, the operation principle of the non-contact drive display device 1B will be described with reference to FIG. 5 (see FIG. 1 as appropriate).

  As shown in FIG. 5A, when the drive signal from the signal source 40 is input, the drive-side inductor 3L generates a magnetic field B corresponding to the drive signal. The display-side inductor 29L generates an electromotive force (drive signal) according to the magnetic field B. That is, the non-contact drive display device 1 can transmit a drive signal between the drive-side inductor 3L and the display-side inductor 29L that are not in contact with each other by electromagnetic induction.

  As shown in FIG. 5B, when the resonance frequency of the parallel resonance circuit 29 matches the frequency of the drive signal, the parallel resonance circuit 29 resonates. At this time, since the impedance of the parallel resonance circuit 29 becomes infinite, the electromotive force (drive signal) E is output to the display element 23 without being transmitted through the parallel resonance circuit 29, and the display element 23 emits light according to the drive signal. To do.

  On the other hand, as shown in FIG. 5C, when the resonance frequency of the parallel resonance circuit 29 and the frequency of the drive signal do not match, the parallel resonance circuit 29 does not resonate. At this time, the electromotive force (drive signal) E almost flows into the parallel resonance circuit 29, and the display element 23 does not emit light. That is, the non-contact drive display device 1 </ b> B can control (select) the display element 23 that emits light according to the relationship between the frequency of the drive signal and the resonance frequency of the parallel resonance circuit 29. Therefore, in the non-contact drive display device 1, it is preferable that the parallel resonance circuits 29 have different resonance frequencies.

  As described above, the non-contact drive display device 1B can transmit a drive signal by electromagnetic induction between the drive circuit 31 and the display circuit 21 that are not in contact with each other. As a result, the non-contact drive display device 1B can manufacture the display substrate 2 and the drive substrate 3 separately, so that there is almost no adverse effect on the display element 23 due to the high heat treatment in the drive substrate manufacturing process. In addition, since the non-contact drive type display device 1B can easily separate the display substrate 2 and the drive substrate 3 even after completion, only one of the display substrate 2 and the drive substrate 3 can be replaced or repaired. . Further, the non-contact drive display device 1B does not require a driving TFT. Thus, the non-contact drive display device 1B according to the second embodiment is easy to manufacture and maintain, and is low in cost.

Example 1
Examples of the present invention will be described below. In Example 1, the operation principle of the non-contact drive display device 1 according to the first embodiment of the present invention was verified (see FIG. 1 as appropriate). As shown in FIG. 6, the non-contact drive display device 1 according to the first embodiment forms two display circuits 21 a and 21 b on the display substrate 2 and drives side inductors corresponding to the display circuits 21 a and 21 b. 3La and 3Lb are formed on the drive substrate 3. In FIG. 6, the upper side corresponds to the display substrate 2 and the lower side corresponds to the drive substrate 3. In FIG. 6, the drive circuit 31 is not shown.

  Each of the display elements 23a and 23b is an LED that emits green light, and the light emission start voltage is 2.6V. The display-side inductor 25La had an inductance of 3 μH. The display-side inductor 25Lb had an inductance of 2 μH. Further, the capacitors 25Ca and 25Cb both have a capacitance of 30 pF.

  The drive-side inductors 3La and 3Lb both had an inductance of 60 μH. A holding member (not shown) held the display substrate 2 and the drive substrate 3 so that the distance between the display circuits 21a and 21b and the drive-side inductors 3La and 3Lb was 1 mm. Then, the signal source 40 outputs a 7 Vpp sine wave drive signal to the drive circuit while gradually changing the frequency. At this time, it was verified by visual observation how the display elements 23a and 23b are lit.

  The display element 23a emitted light when the frequency of the drive signal was between 19 MHz and 21 MHz. On the other hand, the display element 23b emitted light when the frequency of the drive signal was between 25 MHz and 27 MHz. Thus, the frequency at which the display elements 23a and 23b are turned on is considered to be different from the resonance frequencies of the display-side inductors 25La and 251b connected to the display elements 23a and 23b. .

  Next, the signal source 40 sweeps and outputs a 7 Vpp sine wave drive signal from 15 MHz to 25 MHz in a cycle of 499 msec. At this time, it was verified by visual observation how the display elements 23a and 23b are lit.

  The display element 23a emitted light when the frequency of the drive signal was 19 MHz to 21 MHz. The display element 23b emitted light when the frequency of the drive signal was 25 MHz. From this, it was found that the display elements 23a and 23b that emit light can be controlled (selected) by changing the frequency of the drive signal.

  Furthermore, it was verified that the drive signal was transmitted by electromagnetic induction. Specifically, a drive signal having a frequency at which the display element 23a emits light is input, and the distance between the display substrate 2 and the drive substrate 3 is gradually increased. At this time, the lighting state of the display elements 23a and 23b was visually observed.

  When the distance between the display substrate 2 and the drive substrate 3 became 5 cm, the display element 23a stopped emitting light. From this, it was found that in the non-contact drive display device 1, the drive signal is transmitted between the drive circuit 31 and the display circuit 21a that are not in contact with each other by electromagnetic induction.

(Example 2)
Example 2 will be described below (see FIGS. 1 and 2 as appropriate). Example 2 is an example in which the non-contact drive display device 1 according to the first embodiment of the present invention is applied to an outdoor LED display.

  Here, as shown in FIG. 7, when the capacitance of the capacitor 25C is constant (885 pF) and the resonance frequency range is about 5 MHz to 17 MHz, the display-side inductor 25L has an inductance of 0.1 μH to 1.1 μH. It becomes. That is, when applied to a 100-line (QVGA) LED display, pixel selectivity can be ensured by dividing the range of 0.1 μH to 1.1 μH into 100 equal parts every 0.01 μH. As shown in FIG. 7, since the relationship between the inductance and the resonance frequency is non-linear, the portion where the change in the resonance frequency with respect to the inductance is large (the portion where the inclination is large in FIG. 7) may be divided more finely.

  In an outdoor LED display, for example, the pixel pitch is about 10 mm to 20 mm. Generally, in a resonance circuit, the Q value increases as the capacitance and the series resistance are reduced. For these reasons, in the second embodiment, it is sufficient that the Q value is about several tens. Therefore, the series resistance may be set to 1Ω or less. Currently, inductors on the order of μH with a series resistance of 1Ω are commercially available. That is, the non-contact drive display device 1 according to the present invention can be sufficiently realized by using a commercially available package as an outdoor LED display.

As described above, using a commercially available package may increase the cost. Therefore, consider forming a resonant circuit directly on the substrate. Specifically, when the display-side inductor 25L is a spiral inductor having an average radius of 3 mm, a coil area width of 4 mm, and 14 turns, the inductance is 1.0 μH. At this time, the display-side inductor 25L has a pitch between the electrodes of 0.28 mm and can be formed relatively easily. Further, the capacitor 25C has a relative dielectric constant of 1, a dielectric area of 10 × 10 mm ² and a dielectric thickness of 10 μm, the capacitance is 885 pF. Thus, the capacitor 25C has a sufficiently realizable size. That is, the non-contact drive type display device 1 according to the present invention can be sufficiently realized by a method of directly forming a resonance circuit on a substrate as an outdoor LED display.

(Reference Example 1)
Hereinafter, Reference Example 1 will be described (see FIGS. 1 and 2 as appropriate). In Reference Example 1, application of the non-contact drive display device 1 according to the first embodiment of the present invention to a high-definition display is examined.

Since the values of the inductance and the capacitance are proportional to the area of the pixel, when the area of the pixel is reduced to 0.1 × 0.1 mm ² , the values of the inductance and the capacitance are 1/100 and 1/100, respectively. It will be 10,000. Therefore, in order to keep the values of inductance and capacitance at the same level as in the second embodiment, the display-side inductor 25L has a core material (for example, iron, cobalt, or the like) having a relative magnetic permeability of 10 to 10,000 at the center. Nickel). The capacitor 25C is a dielectric having a high relative dielectric constant of 10 to 5000 (for example, strontium titanate, barium titanate or lead zirconate titanate), and the thickness of the dielectric is 0.01 micrometers or more. Decrease the thickness to 5 micrometers or less. The display-side inductor 25L and the capacitor 25C can be formed without any problem. From this, there is no problem in high definition, and the non-contact drive type display device 1 according to the present invention can be sufficiently realized as a high definition display.

1, 1B Non-contact drive type display device 2 Display substrate 21, 21a, 21b Display circuit 23, 23a, 23b Display element 25 Series resonance circuit 25C, 25Ca, 25Cb, 29C Capacitor 25L, 25La, 25Lb, 29L Display side inductor 27 Input Inductor 29 Parallel resonant circuit 3 Driving substrates 3L, 3La, 3Lb Driving inductor 3R Resistor 31 Driving circuit 40 Signal source 50 Holding member 51 Edge 53 Projection

Claims (5)

A display substrate on which a display circuit including a resonance circuit having a predetermined resonance frequency and a display element is formed and a drive substrate on which a drive circuit that outputs a drive signal for driving the display circuit is formed face each other. A non-contact drive type display device that transmits the drive signal from the drive circuit to the display circuit by electromagnetic induction,
The drive board includes a drive-side inductor that outputs a drive signal generated by the drive circuit,
The display circuit outputs the drive signal to the display element when the frequency of the drive signal input from the drive-side inductor matches the resonance frequency of the resonance circuit included in the display circuit. A non-contact drive type display device. The resonant circuit is a series resonant circuit in which a display-side inductor and a capacitor to which the drive signal is input from the drive-side inductor are connected in series.
The non-contact drive display device according to claim 1, wherein the display circuit includes the display element and the series resonant circuit connected in series. The resonant circuit is a parallel resonant circuit in which a display-side inductor and a capacitor are connected in parallel.
The display circuit further includes an input inductor to which the drive signal is input from the drive inductor, and the display element and the parallel resonant circuit are connected in series to the input inductor. The non-contact drive type display device according to claim 1. The display-side inductor includes a core material having a relative magnetic permeability of 10 or more and 10,000 or less,
4. The capacitor according to claim 1, wherein the capacitor includes a dielectric having a thickness of 0.01 μm or more and 5 μm or less and a relative dielectric constant of 10 or more and 5000 or less. The non-contact drive type display device according to any one of the above.   5. The non-contact drive display device according to claim 1, further comprising a holding member that holds the display substrate and the drive substrate at a predetermined interval.

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