electronic machines

Abstract

To provide an electronic device having a reinforcing plate with appropriate stiffness, and configured to properly detect pointed positions through an electromagnetic-induction position detection sensor mounted thereon.SOLUTION: An electronic device includes a reinforcing plate 22 arranged between a display element 21 and a position detection sensor 23 of electromagnetic induction type disposed on a back side of the display element 21. The reinforcing plate 22 includes a slit section corresponding to an entire surface of a display screen of the display element 21. The slit section has first-type slits extending in a vertical direction of the display screen and second-type slits extending in a horizontal direction, the slits being provided uniformly in a manner having substantially the same opening dimensions. Accordingly, stiffness can be maintained over the entire surface of the slit section of the reinforcing plate while allowing a uniform amount of signals to pass (transmitted) through the entire surface of the slit section.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This invention relates to an electronic device configured with a display device and a position detection sensor, such as a high-function mobile phone terminal called a smartphone or a tablet PC (Personal Computer).

Background Art

[0002] So-called flexible display elements having flexibility, such as organic electroluminescence displays and electronic paper displays, have come to be used in various electronic devices such as high-function phone terminals, tablet PCs, and electronic book readers. Since the flexible display element is flexible like paper and can be folded, it can be considered to be used as a display element of a foldable mobile terminal called a foldable terminal.

[0003] In the case of a foldable mobile terminal, since it cannot be folded, a hard protective member such as reinforced glass cannot be arranged on the display screen of the display element. In this case, the overall strength of the mobile terminal becomes insufficient, and there is a possibility of causing problems such as malfunction or breakage due to an impact applied to the display screen, for example. In order to solve such problems, it is conceivable to arrange a reinforcing plate formed of metal or the like on the back side of the flexible display element so that it can be folded.

[0004] It is conceivable to mount an electromagnetic induction type position detection sensor or a capacitance type position detection sensor on a foldable mobile terminal. When performing drawing input of a fine figure or the like, it is desirable to mount an electromagnetic induction type position detection sensor so that drawing input can be performed with an electromagnetic induction type position indicator (electronic pen). However, since the electromagnetic induction type position detection sensor is non-transparent, in the case of a foldable terminal using this, the electromagnetic induction type position detection sensor is arranged on the back side of the flexible display element.

[0005] In this case, if a reinforcing plate is placed between the flexible display element and the electromagnetic induction type position detection sensor, it becomes impossible to detect the indicated position. This is because, in the case of an electromagnetic induction type position detection sensor, it is necessary to send and receive signals (magnetic flux) between the sensor and the position indicator (electronic pen), but the reinforcing plate would obstruct the sending and receiving of magnetic flux. Therefore, as in the invention disclosed in Patent Document 1 described later, it is conceivable to make slits (cuts) in the reinforcing plate.

[0006] In the invention disclosed in Patent Document 1, a grounding conductor layer (solid electrode) is provided between the upper capacitive position detection sensor and the lower electromagnetic induction position detection sensor to stabilize the signal of the capacitive position detection sensor. This conductor layer is formed by arranging multiple slits in the vertical direction (up and down direction) of the operating surface, with one slit extending horizontally (left and right) along the operating surface. This enables good detection of the indicated position by the upper capacitive position detection sensor. Furthermore, it enables mutual transmission and reception of signals between the lower electromagnetic induction position detection sensor and the electromagnetic induction position indicator, allowing for good detection of the indicated position through the lower electromagnetic induction position detection sensor. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2007-157107 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, in the case of the invention disclosed in Patent Document 1, as described above, the conductive layer is formed by arranging multiple slits in the vertical direction of the operating surface, with one slit extending laterally from the operating surface. Therefore, it is thought that there may be a difference in the signal levels transmitted and received depending on whether or not there is a slit on the loop coil that extends laterally from the electromagnetic induction type position detection sensor, making it difficult to detect the appropriate indication position. In other words, in devices that require wide-area and highly accurate position detection in recent years, the invention disclosed in Patent Document 1 cannot be applied because it is not possible to make the signals transmitted and received between the electromagnetic induction type position detection sensor and the electromagnetic induction type position indicator uniform at any position on the operating surface.

[0009] In this case, for example, it is conceivable to arrange multiple slits that are extended vertically in a horizontal direction between slits that are extended horizontally in the conductive layer. This is to increase the area of ​​the slits and enable the transmission and reception of signals at the same level at any position on the operating surface. Accordingly, it is conceivable to similarly increase the area of ​​the slits in the reinforcing plate provided between the flexible display element and the electromagnetic induction type position detection sensor. However, simply increasing the area of ​​the slits in the reinforcing plate would reduce the overall rigidity of the reinforcing plate, making it impossible to obtain the desired strength.

[0010] In view of the above, the present invention aims to provide an electronic device that can appropriately detect a designated position through an electromagnetic induction type position detection sensor while providing appropriate strength using a reinforcing plate. [Means for solving the problem]

[0011] To solve the above problems, Display element and A first position detection sensor of the electromagnetic induction type, disposed on the back side of the display element, which detects the position indicated on the display screen of the display element during operation, A reinforcing plate interposed between the display element and the first position detection sensor, having a slit portion corresponding to the entire surface of the display screen, Equipped with, The slit portion has a first type of slit and a second type of slit, each of the first type of slits extending vertically across the display screen, each of the second type of slits extending horizontally across the display screen, and the first type and the second type of slits have substantially the same opening. area They are uniformly provided in a manner having the following characteristics: The present invention provides an electronic device characterized by the following features. [Brief explanation of the drawing]

[0012] [Figure 1] This is a diagram illustrating a portable terminal configured to apply one embodiment of the electronic device of this invention. [Figure 2] This is a diagram illustrating the flexible part mounted on the mobile terminal of this embodiment. [Figure 3] This is a diagram illustrating the flexible part mounted on the mobile terminal of this embodiment. [Figure 4] This is a diagram illustrating the reinforcing plate for the flexible part of a mobile terminal according to an embodiment. [Figure 5] This is a diagram illustrating the bent portion of the reinforcing plate of the flexible part of the mobile terminal according to the embodiment. [Figure 6] This is a block diagram illustrating an example configuration of an electromagnetic induction-based position detection device. [Figure 7] This figure illustrates another example of a flexible part mounted on a mobile terminal according to the embodiment. [Figure 8] Figure 7 is a diagram illustrating an example of the configuration of the flexible part shown. [Figure 9] This diagram illustrates an example configuration of a capacitive position detection device. [Figure 10] This diagram illustrates the shape pattern of the slits provided in the slit portion of the reinforcing plate.

Best Mode for Carrying Out the Invention

[0013] Hereinafter, an embodiment of an electronic device according to this invention will be described with reference to the drawings. This invention is applicable to various electronic devices equipped with a display element and a position detection sensor of an electromagnetic induction method. However, this invention is more preferably applied to a foldable portable terminal such as a foldable terminal. Therefore, hereinafter, the case where the electronic device according to this invention is applied to a foldable portable terminal will be described as an example.

[0014] [Appearance of Portable Terminal 1, etc.] FIG. 1 is a diagram for explaining a foldable portable terminal (hereinafter, simply referred to as a portable terminal) 1 configured by applying an embodiment of the electronic device of this invention. FIG. 1(A) is a perspective view of the portable terminal ① in an open state. FIG. 1(B) is a side view of the portable terminal ① in an open state. FIG. 1(C) is a side view of the portable terminal ① in a state of being folded in two. As shown in FIGS. 1(A) and (B), the portable terminal ① has a first housing 11 and a second housing 12 connected by a hinge (hinge) provided in the cover portion 13. Thereby, as shown in FIG. 1(C), the portable terminal ① can be folded in two so that the first housing 11 and the second housing 12 face each other.

[0015] The portable terminal ① is provided with a flexible portion 2. The flexible portion 2 is configured by laminating an organic electroluminescence display such as an OLED (Organic Light-Emitting Diode) or a light-emitting polymer, a position detection sensor of an electromagnetic induction method, and the like. The organic electroluminescence display has flexibility and is a flexible display element that can be bent like paper. In addition, the position detection sensor of the electromagnetic induction method is configured using a flexible substrate, and its thickness is also as thin as about 12 μm (micrometer), for example, so it can be bent like paper.

[0016] It should be noted that in the original text, there is an unclear "①" in the description of "FIG. 1(A) is a perspective view of the portable terminal ① in an open state." in line 12. It is translated as "①" here for the sake of consistency with the original text. You may need to check and correct this if it is an error in the original.Therefore, when the mobile terminal 1 is open, the flexible part 2 forms a single display screen and a position detection area corresponding to this display screen over a wide area encompassing the combined top surfaces of the first and second housings, which are visible to the user, as shown in Figures 1(A) and (B). Furthermore, when the mobile terminal 1 is closed, the flexible part 2 can be folded in half as shown by the dotted line in Figure 1(C), positioned inside the opposing first and second housings, and reduced to half the size it is when the mobile terminal 1 is open.

[0017] Thus, because the mobile terminal 1 is foldable, tempered glass cannot be placed on the display screen of the flexible display element. Of course, it is possible to place tempered glass on the upper surface of the first housing 11 and the upper surface of the second housing 12 separately. However, in this case, a connection point between the two tempered glass pieces would be created at the boundary between the upper surface of the first housing 11 and the upper surface of the second housing 12, making it impossible to achieve a seamless, single display screen.

[0018] Therefore, in the mobile terminal 1 of this embodiment, a reinforcing plate is provided on the flexible part 2. This is done to maintain a high level of strength in the mobile terminal 1. However, there is a concern that the reinforcing plate may affect the detection of the indicated position through the electromagnetic induction type position detection sensor, making it impossible to properly detect the indicated position. Therefore, in the mobile terminal 1, the reinforcing plate is also modified so that the detection of the indicated position through the electromagnetic induction type position detection sensor can be performed properly.

[0019] [Example configuration of flexible section 2] Figures 2 and 3 are diagrams illustrating the flexible section 2 mounted on the mobile terminal 1. As shown in Figure 2, the flexible section 2 mounted on the mobile terminal 1 has a four-layer structure. Specifically, the top layer is a flexible display element 21, and a reinforcing plate 22 is provided on the back side of the flexible display element 21. An electromagnetic induction type position detection sensor (first position detection sensor) 23 is provided on the back side of the reinforcing plate 22, and a metal sheet 24 is provided on the back side of the position detection sensor 23. Thus, in this embodiment, the reinforcing plate 22 is provided between the flexible display element 21 and the electromagnetic induction type position detection sensor 23.

[0020] As an example, the thickness of each layer in the flexible section 2 is approximately 200 μm to 500 μm for the flexible display element 21, 150 μm for the reinforcing plate 22, 12 μm for the position detection sensor 23, and 100 μm for the metal sheet 24, as shown in Figure 3. In this embodiment, the metal sheet 24 has a magnetic layer with a thickness of 50 μm on the side facing the position detection sensor 23, and a metal layer with a thickness of 50 μm below it. As a result, the magnetic flux generated by the electromagnetic induction type position detection sensor 23 passes through the magnetic layer without penetrating the metal layer of the metal sheet 24 and heads towards the display element. Because there is little magnetic flux penetrating the metal layer, the generation of eddy currents can be suppressed, and the magnetic flux can not be attenuated. In addition, the metal layer of the metal sheet 24 prevents the magnetic flux generated by the position detection sensor 23 from reaching below the metal layer, and also prevents the influence of magnetism from the electronic circuit located below the metal sheet 24.

[0021] The reinforcing plate 22 should preferably be made of a material that does not easily generate eddy currents, so as to allow magnetic flux to pass through appropriately and not have an electrical effect on the position detection sensor 23. In other words, it is desirable that it be made of a non-magnetic and low-conductivity material. For this reason, in this embodiment, the reinforcing plate 22 is made of stainless steel. More specifically, the reinforcing plate 22 is made of stainless steel material with JIS steel grade number SUS316.

[0022] Stainless steel material with JIS steel grade number SUS316 is suitable for use in the reinforcing plate 22 because it is non-magnetic, does not easily exhibit magnetic poles, has high electrical resistance and does not easily generate eddy currents, and also has high rigidity. Furthermore, as shown in Figure 3, the reinforcing plate 22 has 1.5 times the thickness of the metal sheet 24, which can increase the strength of the mobile terminal 1. It should be noted that the reinforcing plate 22 is not limited to being made of SUS316 stainless steel material. It is of course possible to form it from other materials that are non-magnetic, have low conductivity, and have the desired rigidity, such as hard resin.

[0023] Even though the reinforcing plate 22 is made of a non-magnetic material with high electrical resistance, it still has a certain thickness. This can interfere with the transmission and reception of signals (magnetic flux) between the electromagnetic induction type position detection sensor 23 and an electromagnetic induction type electronic pen (position indicator) (not shown). Ideally, the magnetic flux should pass uniformly through all positions within the position detection area of ​​the position detection sensor 23 between the electromagnetic induction type position detection sensor 23 and the electromagnetic induction type electronic pen. Therefore, slits are provided in the reinforcing plate 22. In this case, depending on how the slits are provided, it is thought that the rigidity of the reinforcing plate 22 may be reduced, making it impossible to provide sufficient strength to the mobile terminal 1.

[0024] Furthermore, since the reinforcing plate 22 is provided on the back side of the flexible display element 21, the unevenness of the reinforcing plate 22 caused by the slits could potentially cause display inconsistencies. Also, because the flexible display element 21 is thin and flexible, the unevenness of the slits formed on the reinforcing plate 22, which is disposed on the back side of the flexible display element 21, could affect the thickness of the drawn lines. In other words, the thickness of the drawn lines may not be uniform, resulting in thin and thick parts, and potentially creating a wavy line.

[0025] Therefore, when slits are provided in the reinforcing plate 22, the following three conditions must be satisfied: (1) the magnetic flux passes uniformly at all positions in the position detection area; (2) the desired rigidity can be maintained; and (3) there should be no unevenness in density to prevent display irregularities or wavy image distortion. Furthermore, as will be described later, the electromagnetic induction type position detection sensor 23 is constructed by arranging multiple X-axis loop coils extended in the Y-axis direction (vertical direction) in the X-axis direction (horizontal direction), and multiple Y-axis loop coils extended in the X-axis direction (horizontal direction) in the Y-axis direction (vertical direction). In this case, the X-axis loop coils are composed of straight lines in the vertical direction, and the Y-axis loop coils are composed of straight lines in the horizontal direction, so the structural characteristics of such an electromagnetic induction type position detection sensor must also be considered.

[0026] Considering these factors, in this embodiment, slits extending in the vertical direction (Y-axis direction) of the display screen and slits extending in the horizontal direction (X-axis direction) of the display screen are provided uniformly on the reinforcing plate 22 without density, so that the opening area is approximately the same. Furthermore, the display screen of the flexible display element 21, the slit area of ​​the reinforcing plate 22 where the slits are provided, and the position detection area of ​​the electromagnetic induction type position detection sensor are made to be approximately the same in shape and area. In an even more optimal case, if the slit area is slightly wider, the influence of the frame part described later can be further reduced, and accuracy can be improved.

[0027] This allows the strength of the mobile terminal 1 to be increased by a reinforcing plate 22 with slits formed to maintain rigidity across the entire display screen of the flexible display element 21. Moreover, the reinforcing plate 22 has slits extending in the vertical direction of the display screen and slits extending in the horizontal direction of the display screen, uniformly provided without density, so that the opening area is approximately the same. As a result, the unevenness caused by the formation of the slits is not noticeable, and the transmission and reception of magnetic flux can be performed appropriately without interfering.

[0028] [Example of the configuration of the reinforcing plate 22] Figure 4 is a diagram illustrating the reinforcing plate 22 of the flexible part 2 mounted on the mobile terminal 1. In both Figures 4(A) and (B), an H-shaped slit, similar in shape to the letter H, is formed by arranging H-shaped slits in the vertical and horizontal directions, respectively, by connecting the midpoints of two parallel rod-shaped slits of the same length with a single rod-shaped slit. In the examples shown in Figures 4(A) and (B), the width of one rod-shaped slit (width in the direction intersecting the longitudinal direction) is 0.5 mm.

[0029] Furthermore, as shown in black on the upper left side of Figure 4(A), a slit area is formed on the reinforcing plate 22 using three types of H-shaped slits of different lengths, connecting the midpoints of two parallel rod-shaped slits of the same length. As shown in black on the upper left side of Figure 4(B), a slit area is formed on the reinforcing plate 22 using one type of H-shaped slit of common length, connecting the midpoints of two parallel rod-shaped slits of the same length.

[0030] The examples in Figures 4(A) and (B) show that the H-shaped slits are arranged alternately in the vertical and horizontal directions, with slits having two slits of equal length positioned horizontally and slits having two slits of equal length positioned vertically. In both examples in Figures 4(A) and (B), the slits can be uniformly arranged without density in the slit area of ​​the reinforcing plate 22. That is, the opening area of ​​the slits extending vertically and the opening area of ​​the slits extending horizontally are approximately equal within the slit area. Therefore, even the parts of the base metal without slits within the slit area are uniformly distributed within the slit area.

[0031] As a result, even if slits are provided in the reinforcing plate 22, the overall rigidity of the reinforcing plate 22 is not deteriorated. Moreover, since H-shaped slits can be uniformly provided across the entire slit area without density, it does not cause unevenness on the display screen, does not cause display irregularities, and does not cause drawn lines to become wavy. Of course, the uniformly provided H-shaped slits allow magnetic flux to pass through, and further suppress the generation of eddy currents caused by magnetic flux passing through the reinforcing plate 22, making it possible to transmit and receive magnetic flux properly without hindering it.

[0032] The difference between Figure 4(A) and Figure 4(B) lies in the magnetic flux coupling rate. When the reinforcing plate 22 is absent, and the magnetic flux coupling rate between the position detection sensor 23 and the position indicator is set to 100%, the coupling rate in Figure 4(A) is 89.1%, while the coupling rate in Figure 4(B) is 88.1%. Experiments have verified that using slits of different lengths improves the coupling rate.

[0033] [Structure of the bent portion of the reinforcing plate] Figure 5 is a diagram illustrating the bending portion of the reinforcing plate 22 of the flexible part 2 mounted on the mobile terminal 1. If slits are provided on the entire surface of the reinforcing plate 22 in the manner shown in Figures 4(A) and (B), the mobile terminal 1 will not be able to be folded smoothly as shown in Figure 1(C). This is because there is a base metal portion that extends in a direction intersecting the bending portion at the bending portion, making it difficult to bend and prone to damage.

[0034] Therefore, as shown in Figure 5(A), a bent portion 22C is provided in the central part of the reinforcing plate 22, with the left side designated as the left slit portion 22L and the right side as the right slit portion 22R. The left slit portion 22L and the right slit portion 22R are provided with uniformly spaced H-shaped slits on their entire surfaces, as shown in Figure 4(A) or Figure 4(B). Furthermore, as shown in Figure 5(B), the bent portion 22C is formed in a mesh-like manner, having multiple roughly rhombus-shaped openings. By forming the bent portion 22C in a mesh-like manner in this way, the bent portion 22C can stretch slightly in the directions indicated by arrows a and b, and the bent portion 22C can be folded (folded in half) without difficulty.

[0035] Furthermore, as shown in Figure 5, a frame section 22FL is provided around the reinforcing plate 22, which basically does not have slits. The inside of this frame section 22FL is the slit area, which corresponds to the display screen of the flexible display element and the position detection area of ​​the electromagnetic induction type position detection sensor. Therefore, the frame section does not overlap with the display screen or the position detection area. Also, the frame section 22FL basically does not have slits. To prevent disturbance of the magnetic flux by the frame section 22FL, making the slit area the same size as or slightly larger than the position detection area will further improve the accuracy of position indication even at the edges of the display screen.

[0036] Furthermore, the upper and lower ends of the folding portion 22C may be provided with mesh-like slits, similar to the other parts of the folding portion 22C. This is to allow for smooth folding and unfolding of the mobile terminal 1. It is also conceivable that the left slit portion 22L and the right slit portion 22R may also be provided with mesh-like slits, similar to the folding portion 22C. However, between mesh-like slits (Figure 5(B)) and H-shaped slits (Figure 4(A), (B)), the H-shaped slits allow for higher rigidity to be maintained.

[0037] Furthermore, the bent portion 22C may be provided with an I-shaped slit resembling the letter I along the fold. That is, the bent portion 22C may be constructed by providing multiple slits that extend along the fold. In this case, it becomes possible to bend the material smoothly without forming a portion of the base metal that extends in a direction intersecting the fold.

[0038] Furthermore, because the shape of the slits differs between the left slit section 22L, the right slit section 22R, and the bent section 22C, the coupling rate of the magnetic flux differs, which may lead to misdetection of the indicated position in the bent section 22C. For this reason, as will be described later, the detection output of the position detection sensor 23 in the bent section 22C is corrected. This makes it possible to detect the indicated position in the same way as in the areas corresponding to the left slit section 22L and the right slit section 22R, which are equipped with H-shaped slits.

[0039] [Example configuration of an electromagnetic induction-based position detection device] Figure 6 is a block diagram illustrating an example configuration of a position detection device that includes an electromagnetic induction type position detection sensor 23. The electronic pen 300 is of the electromagnetic induction type and, as shown in the upper left of Figure 6, comprises a resonant circuit configured by connecting a coil L for transmitting and receiving signals, a pressure detection unit Cv which is a variable capacitance capacitor, and a resonant capacitor Cf, etc., in parallel.

[0040] The position detection device 100 includes a position detection sensor 23 formed by stacking an X-axis loop coil group 23X and a Y-axis loop coil group 23Y. The loop coils X1, X2, ..., X of the X-axis loop coil group 23X 40 and loop coils Y1, Y2, ..., Y of the Y-axis loop coil group 23Y 30Each of these may be a single turn or a multi-turn sequence of two or more turns. As described above, such position detection sensors 23 are positioned below the reinforcing plate 22, which is located on the back side of the flexible display element 21. These position detection sensors 23 are connected to the position detection circuit 101, thereby forming the position detection device 100 as a whole.

[0041] The position detection circuit 101 is located inside the first housing 11 or the second housing 12 on the lower side of the metal sheet 24. The position detection circuit 101 consists of an oscillator 102, a current driver 103, a selection circuit 104, a switching connection circuit 105, a receiving amplifier 106, a position detection circuit 107, a pen pressure detection circuit 108, and a processing control unit 109. As shown in Figure 6, the loop coil group 23X in the X-axis direction and the loop coil group 23Y in the Y-axis direction of the position detection sensor 23 are connected to the selection circuit 104. The selection circuit 104 sequentially selects one of the two loop coil groups 23X and 23Y in accordance with the control of the processing control unit 109.

[0042] The processing control unit 109 is composed of a microprocessor. The processing control unit 109 controls the selection of the loop coil in the selection circuit 104 and the switching of the switching connection circuit 105, as well as the processing timing in the position detection circuit 107 and the pressure sensitivity detection circuit 108.

[0043] The oscillator 102 generates an AC signal with frequency f0. The oscillator 102 supplies the generated AC signal to the current driver 103 and the pressure sensitivity detection circuit 108. The current driver 103 converts the AC signal supplied from the oscillator 102 into current and sends it to the switching connection circuit 105. The switching connection circuit 105, under control from the processing control unit 109, switches the connection destination (transmitting terminal T, receiving terminal R) to which the loop coil selected by the selection circuit 104 is connected. Of these connection destinations, the current driver 103 is connected to the transmitting terminal T, and the receiving amplifier 106 is connected to the receiving terminal R.

[0044] The switching connection circuit 105 is switched to the transmitting terminal T side during the transmission period and to the receiving terminal R side during the reception period. As a result, during the transmission period, the loop coil, which receives current from the current driver 103 through the transmitting terminal T, generates a magnetic field, which is transmitted to the electronic pen 300 and acts on the resonant circuit of the electronic pen 300. In this case, the resonant circuit of the electronic pen 300 generates a position indication signal (radio wave) and transmits it to the position detection sensor 23.

[0045] On the other hand, during the reception period, the loop coil selected by the selection circuit 104 is connected to the receiving amplifier 106 through the receiving terminal R. When the loop coil is subjected to a magnetic field from the electronic pen 300, an induced voltage is generated in the loop coil, and this induced voltage is sent to the receiving amplifier 106 via the selection circuit 104 and the switching connection circuit 105. The receiving amplifier 106 amplifies the induced voltage supplied from the loop coil and sends it to the position detection circuit 107 and the pen pressure detection circuit 108.

[0046] In other words, an induced voltage is generated in each loop coil of the X-axis loop coil group 23X and the Y-axis loop coil group 23Y by the radio waves transmitted from the electronic pen 300. Therefore, the position detection circuit 107 detects the induced voltage (received signal) generated in the loop coils, converts the detected output signal into a digital signal, and outputs it to the processing control unit 109. The processing control unit 109 calculates the coordinate values ​​of the indicated position in the X-axis and Y-axis directions of the electronic pen 300 based on the digital signal from the position detection circuit 107, that is, the voltage value of the induced voltage generated in each loop coil.

[0047] Meanwhile, the pressure sensitivity detection circuit 108 synchronously detects the output signal of the receiving amplifier 106 using the AC signal from the oscillator 102 to obtain a signal with a level corresponding to the phase difference (frequency shift) between them. In this case, it converts the signal corresponding to the phase difference (frequency shift) into a digital signal and outputs it to the processing control unit 109. The processing control unit 109 detects the pressure applied to the electronic pen 300 based on the level of the digital signal from the pressure sensitivity detection circuit 108, that is, the signal corresponding to the phase difference (frequency shift) between the transmitted radio wave and the received radio wave.

[0048] Furthermore, as mentioned above, the position detection circuit 107 and the pressure detection circuit 108 correct the output signal from the loop coil in the portion of the reinforcing plate 22 that corresponds to the bent portion 22C located on the upper side of the position detection sensor 23. This allows the position detection in the portion of the position detection sensor 23 corresponding to the bent portion 22C to be performed in the same condition as the other portions where the H-shaped slit is provided. Therefore, even when the bent portion 22C is pointed to, the position and pressure can be detected appropriately.

[0049] In this manner, the position detection circuit 101 switches between a signal transmission period and a signal reception period. During the transmission period, it supplies driving power to the electronic pen 300 to drive it, and during the reception period, it receives a signal from the electronic pen 300 to detect the indicated position and pen pressure. This position detection circuit 101 is configured as a circuit board. By connecting the cable portion of the position detection sensor 23 to the position detection circuit 101 configured as a circuit board, the position detection device 100 can be realized and mounted on the mobile terminal 1 as an input device.

[0050] As described above, the mobile terminal 1 of this embodiment has a reinforcing plate 22 between the flexible display element 21 and the electromagnetic induction type position detection sensor 23. However, the reinforcing plate is made of stainless steel such as SUS316, but the parts corresponding to the display screen of the flexible display element 21 and the position detection area of ​​the position detection sensor 23 are uniformly provided with slits. This allows the rigidity of the reinforcing plate 22 to be maintained and strength added to the mobile terminal 1, and also prevents display unevenness on the display screen, while enabling proper transmission and reception of signals between the electromagnetic induction type position detection sensor 23 and the electromagnetic induction type electronic pen 300. Of course, the mobile terminal 1 can also be easily folded and unfolded.

[0051] [Other examples of flexible parts] The flexible part 2 of the mobile terminal 1 in the above-described embodiment was equipped with an electromagnetic induction type position detection sensor 23. However, in addition to the electromagnetic induction type position detection sensor 23, a capacitive type position detection sensor can also be provided. This makes it possible to realize a hybrid mobile terminal 1 that can accept both instruction input using the user's fingers or a so-called electrostatic pen, and instruction input using an electromagnetic induction type electronic pen.

[0052] Figures 7 and 8 are diagrams illustrating the flexible section 2A mounted on the mobile terminal 1A. In the flexible section 2A shown in Figures 7 and 8, parts that are configured in the same way as the parts that constitute the flexible section 2 shown in Figures 2 and 3 are given the same reference numerals, and detailed explanations of those parts are omitted to avoid redundancy. In Figures 7 and 8, the capacitive position detection sensor (second position detection sensor) 25 can be made transparent using thin linear electrodes, and can therefore be placed on the upper side of the flexible display element 21. That is, as shown in Figure 7, the flexible section 2A can be formed by stacking the components in the following order from top to bottom: capacitive position detection sensor 25 → flexible display element 21 → reinforcing plate 22 → electromagnetic induction position detection sensor 23 → metal sheet 24.

[0053] Therefore, as shown in Figure 8, a flexible section 2A can be constructed in which a capacitive position detection sensor 25, which is thinner and more transparent than the electromagnetic induction type position detection sensor 23, is placed on the upper surface side of the flexible display element 21. In this case as well, as shown in Figures 7 and 8, a reinforcing plate 22 is provided between the flexible display element 21 and the electromagnetic coupling type position detection sensor 23. As mentioned above, this reinforcing plate 22 is non-magnetic and has high electrical resistance, so eddy propagation is unlikely to occur.

[0054] Therefore, even with the presence of an electromagnetic induction type position detection sensor 23 that generates an alternating magnetic field, which is a magnetic field whose magnitude and direction repeatedly change over time, eddy currents are unlikely to be generated in the reinforcing plate 22. As a result, it does not affect the detection of the indicated position through the capacitive type position detection sensor 25. In other words, it is possible to construct a mobile terminal 1A that can perform both the detection of the indicated position through the capacitive type position detection sensor 25 and the detection of the indicated position using the electromagnetic induction type position detection sensor 23 well. Moreover, the presence of the reinforcing plate 22 increases the strength across the entire upper surface of the mobile terminal 1 where the display screen of the flexible display element 21 is located, so a mobile terminal 1 with high strength can be realized even when it is open.

[0055] [Example configuration of a capacitive position detection device] Figure 9 is a diagram illustrating an example configuration of a capacitive position detection device 200 mounted on a mobile terminal 1A. As shown in Figure 9, the position detection device 200 consists of a position detection sensor 25 and a position detection circuit 210 connected to the position detection sensor 25.

[0056] The position detection sensor 25 is formed by stacking a first conductor group 251 and a second conductor group 252. The first conductor group 251 consists of, for example, multiple first conductors 25Y1 to 25Y extending in the lateral direction (X-axis direction). m These are arranged in parallel along the Y-axis, separated from each other by predetermined distances. The second conductor group 252 consists of multiple second conductors 25X1~25X that extend in a direction intersecting the first conductor, or in this example, in a perpendicular vertical direction (Y-axis direction). nThese are arranged in parallel along the X-axis, separated from each other by a predetermined distance.

[0057] Thus, the position detection sensor 25 of the position detection device 200 is configured to detect the position indicated by the user's finger or a capacitive electronic pen (electrostatic pen) using a sensor pattern formed by crossing the first conductor group 251 and the second conductor group 252. In the explanation of Figure 9, the first conductors 25Y1 to 25Y m When referring to one of them, it is written as the first conductor 25Y, and the second conductor 25X1~25X n When referring to one of the conductors, it shall be written as the second conductor 25X.

[0058] The position detection circuit 210 consists of a selection circuit 211 which serves as an input / output interface with the position detection sensor 25, an amplification circuit 212, a received signal processing circuit 213, and a control circuit 214. The received signal processing circuit 213, although not shown in the diagram, includes a bandpass filter, a detection circuit, a sample-and-hold circuit, and an AD (Analog to Digital) conversion circuit.

[0059] The selection circuit 211 selects one conductor 25Y or 25X from the first conductor group 251 and the second conductor group 252 based on a control signal from the control circuit 214. The conductor selected by the selection circuit 211 is connected to the amplification circuit 212, and a signal corresponding to the change in potential caused by contact by the user's finger or electrostatic pen is detected by the selected conductor and amplified by the amplification circuit 212. The output of this amplification circuit 212 is supplied to the received signal processing circuit 213. The received signal processing circuit 213 band-limits the signal supplied to it, performs detection processing, samples and holds, converts it into a digital signal, and supplies it to the control circuit 214.

[0060] The control circuit 214 controls the selection circuit 211 by supplying control signals to it, and also controls the receiving signal processing circuit 213 by supplying control signals to it, based on a program stored in its internal ROM (Read Only Memory). The control circuit 214 also calculates the position coordinates on the position detection sensor 25, indicated by the user's finger or electrostatic pen, from the digital data from the receiving signal processing circuit 213. When using a so-called active electrostatic pen that sends position indication signals and pen pressure signals, the control circuit 214 can also process the digital data from the receiving signal processing circuit 213 to detect the pen pressure detected by the pressure detection unit of the active electrostatic pen.

[0061] In this way, the position detection device 200 detects the position indicated by the user's finger or electrostatic pen, and supplies this information to, for example, a computer device, enabling it to perform processing corresponding to the icon at the indicated position. In the case of a mobile terminal 1A equipped with both such a capacitive position detection device 200 and the electromagnetic induction type position detection device 100 described with reference to Figure 6, the two can be used interchangeably. That is, simple operations can be performed with the user's finger, and the capacitive position detection device 200 can receive the input. Furthermore, when detailed drawing is desired, the electromagnetic induction type electronic pen 300 can be used, and the electromagnetic induction type position detection device 100 can receive the input.

[0062] Furthermore, even when both a capacitive position detection sensor 25 and an electromagnetic induction position detection sensor 23 are installed, the reinforcing plate 22 maintains its rigidity and provides strength. At the same time, it is possible to properly transmit and receive signals between the electromagnetic induction position detection sensor 23 and the electromagnetic induction electronic pen 300 without causing display unevenness or wavy lines on the display screen. Of course, it is also possible to easily fold and unfold the mobile terminal 1. Moreover, the detection of the indicated position through the capacitive position detection sensor 25 can be performed appropriately without being affected by the electromagnetic induction position detection sensor 23.

[0063] [Effects of the embodiment] According to the above-described embodiment of the mobile terminal 1, by providing a reinforcing plate 22 between the flexible display element 21 and the electromagnetic induction type position detection sensor 23, the mobile terminal 1 can be given strength corresponding to the rigidity of the reinforcing plate 22. Moreover, the reinforcing plate 22 is uniformly provided with slits extending in the vertical direction of the display screen and slits extending in the horizontal direction across the entire surface of the slit area, such that the opening area is approximately the same. As a result, display unevenness is not caused, and magnetic flux transmission and reception can be performed appropriately at any position in the slit area without hindering the transmission and reception of magnetic flux. Furthermore, in the case of the mobile terminal 1A described above, even if a capacitive type position detection sensor 25 is placed on the upper surface side of the flexible display element 21, it is not affected by the electromagnetic induction type position detection sensor 23 due to the action of the reinforcing plate 22. Therefore, the detection of the indicated position through the capacitive type position detection sensor 25 can be performed appropriately.

[0064] [Differentiations, etc.] Figure 10 is a diagram illustrating the shape patterns of the slits provided in the slit portion of the reinforcing plate. In the embodiment described above, as shown in Figure 10(A), an H-shaped slit, similar in shape to the letter H, is used by connecting the midpoints of two parallel slits of the same length with a single slit. However, this is not the only possible shape.

[0065] For example, as shown in Figure 10(B), a single bar-shaped I-shaped slit, similar to the letter I of the alphabet, may be uniformly arranged in the slit area of ​​the reinforcing plate 22, with varying orientations. Alternatively, as shown in Figure 10(C), a T-shaped slit, consisting of a horizontal bar and a vertical bar, similar to the letter T of the alphabet, may be uniformly arranged in the slit area of ​​the reinforcing plate 22, with no significant differences in density. Furthermore, as shown in Figure 10(D), a Z-shaped slit, consisting of two horizontal bars and a diagonal bar connecting them, similar to the letter Z of the alphabet, may be uniformly arranged in the slit area of ​​the reinforcing plate 22, with no significant differences in density.

[0066] Furthermore, slits of different shapes may be combined to form slits in the slit area of ​​the reinforcing plate 22, for example, by combining H-shaped slits with I-shaped slits, or H-shaped slits with T-shaped slits. In addition, the shapes of the slits provided in the slit area of ​​the reinforcing plate 22 can be varied. In this case, the important things are to satisfy all of the following: (1) not to degrade the rigidity of the reinforcing plate 22; (2) not to cause unevenness on the display screen of the flexible display element 21, such as by making the spacing of the slits too large; and (3) to ensure that magnetic flux can be sent and received uniformly at any position in the position detection area of ​​the position detection sensor 23 between the electromagnetic induction type position detection sensor 23 and the electromagnetic induction type electronic pen 300.

[0067] Furthermore, in the above-described embodiment, a flexible display element 21 is used to realize the foldable mobile terminal 1. The flexible display element 21 is not limited to organic electroluminescent displays such as OLEDs or light-emitting polymers. It is also perfectly acceptable to use a display element called electronic paper. Electronic paper is a display medium that retains the advantages of paper, such as visibility and portability, while allowing the display content to be electrically rewritten. In simple terms, the structure of electronic paper is one in which many tiny spheres, each painted white and the other hemisphere black, are embedded in a display. Some of the spheres are charged with static electricity, and by rotating the spheres with an electric field, black characters can be made to appear on a white background. In recent years, some electronic paper displays are capable of displaying color.

[0068] Furthermore, the display element is not limited to a flexible display element; it may also be a so-called panel display such as an LCD (Liquid Crystal Display) or a plasma display. However, by using the present invention, when a flexible display element such as an OLED or electronic paper is used as the display element, strength can be added to the mobile terminal without using tempered glass. Therefore, this invention is more suitable for use when forming a so-called foldable terminal using a flexible display element. [Explanation of Symbols]

[0069] 1, 1A…Mobile terminal, 11…First housing, 12…Second housing, 13…Cover part, 2, 2A…Flexible part, 21…Flexible display element, 22…Reinforcement plate, 22L…Left slit part, 22R…Right slit part, 22C…Bending part, 22FL…Frame part, 23…Electromagnetic induction type position detection sensor, 24…Metal sheet, 25…Capacitive type position detection sensor, 100…Electromagnetic induction type position detection device, 200…Capacitive type position detection device, 300…Electromagnetic induction type electronic pen

Claims

1. Display element and A first position detection sensor of the electromagnetic induction type, disposed on the back side of the display element, which detects the position indicated on the display screen of the display element during operation, A reinforcing plate interposed between the display element and the first position detection sensor, having a slit portion corresponding to the entire surface of the display screen, Equipped with, The slit portion comprises a first type of slit and a second type of slit, each of the first type of slits extending vertically across the display screen, each of the second type of slits extending horizontally across the display screen, and the first and second type of slits are uniformly arranged in such a manner that they have substantially the same opening area. An electronic device characterized by the following features.

2. The electronic device according to claim 1, The outer edge of the reinforcing plate is provided with a frame portion that does not have slits. An electronic device characterized by the following features.

3. The electronic device according to claim 1, The outer edge of the reinforcing plate is provided with a frame portion that does not have slits. The frame portion does not overlap with the display screen of the display element. An electronic device characterized by the following features.

4. The electronic device according to claim 1, The display screen of the display element, the position detection area of ​​the first position detection sensor, and the slit area of ​​the reinforcing plate where the slit is provided are substantially identical in shape and area, and are stacked so as to overlap each other. An electronic device characterized by the following features.

5. The electronic device according to claim 1, The reinforcing plate is formed of a non-magnetic material. An electronic device characterized by the following features.

6. The electronic device according to claim 1, The reinforcing plate is made of stainless steel. An electronic device characterized by the following features.

7. The electronic device according to claim 1, The reinforcing plate is made of stainless steel material with JIS steel grade number SUS316. An electronic device characterized by the following features.

8. The electronic device according to claim 1, The display element and the first position detection sensor are foldable, The reinforcing plate is configured to be foldable, with a bendable portion provided with a slit in a bendable manner at a position where the display element and the first position detection sensor are bent. An electronic device characterized by the following features.

9. The electronic device according to claim 1, The display element and the first position detection sensor are foldable, The reinforcing plate is configured to be foldable, with a bending portion provided with a rod-shaped I-shaped slit along the axis of bending at the position where the display element and the first position detection sensor are bent. An electronic device characterized by the following features.

10. The electronic device according to claim 1, The slits in the reinforcing plate are provided in one of the following shapes: an I-shape with a rod, a T-shape consisting of a horizontal bar and a vertical bar, a Z-shape consisting of two horizontal bars and a diagonal bar connecting them, or an H-shape consisting of two vertical bars and a horizontal bar connecting them. An electronic device characterized by the following features.

11. The electronic device according to claim 1, The display element and the first position detection sensor are foldable, The reinforcing plate is configured to be foldable, and includes a bendable portion with a slit in a bendable manner at a position where the display element and the first position detection sensor are bent. By correcting the detection output of the position detection sensor located below the bent portion of the reinforcing plate, the indicated position on the bent portion becomes detectable. An electronic device characterized by the following features.

12. The electronic device according to claim 1, The display element is composed of one of the following: a liquid crystal display, an organic electroluminescent display, or an electronic paper display. An electronic device characterized by the following features.

13. The electronic device according to claim 1, A second capacitive position detection sensor is provided, which is disposed on the surface side of the display element and detects the indicated position on the display screen of the display element. An electronic device characterized by the following features.

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