TWI658446B - Micro-led touch display panel - Google Patents

Abstract

A micro LED touch display panel includes a plurality of micro LEDs. The micro LED touch display panel further includes a plurality of photodiodes. The plurality of photodiodes detect a touch position by sensing a change in light intensity. The miniature LED touch display panel provided by the embodiment of the present invention detects a touch position by setting a plurality of photodiodes according to a change of an optical signal induced when the plurality of photodiodes touches with or without a finger on the top. Touch technology is incorporated into the micro LED display panel.

Description

Mini LED touch display panel

The present invention relates to the field of display technology, and in particular, to a miniature LED touch display panel.

Micro-LED (Micro Light Emitting Diode) display technology, also known as micro LED or μLED display technology, is an emerging flat-panel display technology. At present, the micro LED panel is a transparent conductive film connected to the N-type doped phosphor layer and connected to the ground via a metal wire. The P-type doped phosphor layer is connected to the positive potential element via the metal wire to light up. Light-emitting diode. However, the current micro-LED display panel does not incorporate touch technology.

In view of the above, it is necessary to provide a miniature LED touch display panel.

The micro LED touch display panel provided in the embodiment of the present invention includes a plurality of micro LEDs, and the plurality of micro LEDs emit light in a forward bias state. The micro LED touch display panel further includes a plurality of photodiodes. The plurality of photodiodes sense a change in luminance under a negative bias state to detect a touch position.

Preferably, each micro LED includes an anode and a cathode, and the forward bias state means that the potential of the anode of the micro LED is higher than the potential of the cathode of the micro LED; The diode includes an anode and a cathode. The negative bias state means that the potential of the anode of the photodiode is lower than the potential of the cathode of the photodiode.

Preferably, the micro LED touch display panel is defined with a plurality of pixel units, and each pixel unit includes a plurality of micro LEDs emitting different colors of light and a photodiode.

Preferably, the plurality of micro LEDs in each pixel unit include a red micro LED, a green micro LED, and a blue micro LED.

Preferably, the red micro LEDs, the green micro LEDs, the blue micro LEDs, and the photodiodes in each pixel unit are arranged in a 2 × 2 matrix.

Preferably, the red micro LED, the green micro LED, the blue micro LED, and the photodiodes in each pixel unit are arranged in a row or a column.

Preferably, the photodiodes of at least two adjacent pixel units constitute one touch unit.

Preferably, the cathode of each photodiode in the touch unit is grounded, and the anode of the plurality of photodiodes in the touch unit is electrically connected to the same negative voltage signal through a wire.

Preferably, the anode of each photodiode in the touch unit is grounded, and the cathode of the plurality of photodiodes in the touch unit is electrically connected to the same positive voltage signal through a wire.

Preferably, the micro LED touch display panel further includes a control circuit for applying a voltage signal to the photodiode, and receiving and processing a light sensing signal of the photodiode.

According to the miniature LED touch display panel provided by the embodiment of the present invention, a plurality of photodiodes are provided, and a light signal sensed by the plurality of photodiodes when a finger is touched on the photodiode is used to detect a touch position, Touch technology is incorporated into the micro LED display panel.

10‧‧‧Mini LED touch display panel

100‧‧‧ Cover glass

200‧‧‧ substrate

300‧‧‧Touch Unit

30‧‧‧ Pixel Unit

31‧‧‧Mini LED

311‧‧‧Red Micro LED

312‧‧‧Green Mini LED

313‧‧‧Blue Mini LED

314‧‧‧ Cathode for Mini LED

315‧‧‧The first N-type doped phosphor layer

316‧‧‧first active layer

317‧‧‧The first P-type doped phosphor layer

318‧‧‧Anode for Micro LED

319‧‧‧Insulation

320‧‧‧through hole

32‧‧‧photodiode

321‧‧‧ Photodiode cathode

322‧‧‧Second N-type doped phosphor layer

325‧‧‧second active layer

323‧‧‧Second P-type doped phosphor layer

324‧‧‧Anode for Photodiode

33‧‧‧first lead

34‧‧‧Second Lead

400‧‧‧Control circuit

FIG. 1A is a schematic cross-sectional view of a micro LED touch display panel according to a preferred embodiment of the present invention.

FIG. 1B is a schematic cross-sectional view of a miniature LED touch display panel according to a preferred embodiment of the present invention when a finger touches it.

2 is a schematic plan view showing the arrangement of a plurality of pixel units of a micro LED touch display panel according to an embodiment of the present invention.

3 is a schematic plan view showing the arrangement of a plurality of pixel units of a micro LED touch display panel according to another embodiment of the present invention.

FIG. 4 is an equivalent circuit diagram of a touch unit of a micro LED touch display panel according to a preferred embodiment of the present invention.

FIG. 5 is another equivalent circuit diagram of a touch unit of a micro LED touch display panel according to a preferred embodiment of the present invention.

6 is a sectional view of a micro LED of a micro LED touch display panel according to a preferred embodiment of the present invention.

FIG. 7 is a cross-sectional view of a photodiode of a miniature LED touch display panel according to a preferred embodiment of the present invention.

The miniature LED described herein refers to an LED having a size in the range of about 1 μm to 100 μm, and more specifically, refers to an LED having a size smaller than 100 μm. The photodiode system described in this article refers to an optical inductor that converts optical signals into electrical signals. Test device.

FIG. 1A is a schematic diagram of a micro LED touch display panel according to a preferred embodiment of the present invention. As shown in FIG. 1A, the micro LED touch display panel 10 includes a substrate 200 and a plurality of micro LEDs 31 and a plurality of photodiodes 32 on the substrate 200. In this embodiment, the plurality of micro LEDs 31 emit light in a forward biased state, and the plurality of photodiodes 32 sense a change in light intensity in a negatively biased state to detect a touch position.

Specifically, each micro LED 31 includes an anode and a cathode, and the forward bias state means that the potential of the anode of the micro LED 31 is higher than the potential of the cathode of the micro LED 31. Each photodiode 32 includes an anode and a cathode. The negative bias state means that the potential of the cathode of the photodiode 32 is higher than the potential of the anode of the photodiode 33.

As shown in FIG. 1A, when there is no finger touch on the micro LED touch display panel 10, the plurality of micro LEDs 31 emit different colors of light for screen display. In this case, the photodiode 32 The highest brightness is collected on the top; as shown in FIG. 1B, when a finger touches on the micro LED touch display panel 10, the plurality of micro LEDs 31 also emit different colors of light for screen display, but in this case Due to the touch action of the finger, the light above part of the photodiode 32 is blocked, so that the light intensity collected on the photodiode 32 at the touch position changes, and the corresponding photoelectricity located at the touch position changes. There is a difference in the light sensing signal (such as the photocurrent I _photo ) of the diode 32. By processing and calculating the difference in the light sensing signal, the coordinates of the touch position can be obtained, thereby realizing the touch function. The display panel incorporates touch technology.

In this embodiment, the substrate 200 is used to carry a plurality of micro LEDs 31 and a plurality of photodiodes 32. In order to ensure the display effect, the substrate 200 is transparent. The micro LED touch display panel 10 further includes a cover glass 100 disposed on a side of the substrate 200 away from the plurality of micro LEDs 31 and the plurality of photodiodes 32. The cover glass 100 is used to protect all Said substrate 200 and the substrate A plurality of micro LEDs 31 and a plurality of photodiodes 32 on 200. The micro-LED touch display panel 10 provided in this embodiment does not require an additional touch screen, so it can effectively reduce the overall thickness of the product.

Please continue to refer to FIG. 1A and FIG. 1B, the micro LED touch display panel 10 defines a plurality of pixel units 30, and each pixel unit 30 includes a plurality of micro LEDs 31 and a photodiode 32 that emit light of different colors. Understandably, the pixel unit 30 and the photodiode 32 do not have to be arranged one-to-one, and other suitable settings may be selected according to actual needs.

2 is a schematic plan view showing the arrangement of a plurality of pixel units of a micro LED touch display panel according to an embodiment of the present invention. As shown in FIG. 2, the plurality of pixel units 30 are arranged in a matrix. Each pixel unit 30 includes a red micro LED 311, a green micro LED 312, a blue micro LED 313, and a photodiode 32. The red micro LEDs 311, the green micro LEDs 312, the blue micro LEDs 313, and the photodiodes 32 in each pixel unit 30 are arranged in a 2 × 2 matrix. Among them, a red micro LED 311 and a green micro LED 312 are arranged in the first row of each pixel unit 30, and a blue micro LED 313 and a photodiode 32 are arranged in the second row of each pixel unit 30. One of the plurality of pixel units 30 is one red micro LED 311 and one green micro LED 312 alternately and periodically arranged, and the other one is a blue micro LED 313 and one photodiode 32 are alternately and periodically arranged. The red pixel LEDs 311 and the blue red LEDs 313 are alternately and periodically arranged in a row of the plurality of pixel units 30, and the green LEDs 312 and a photodiode 32 are alternately and periodically arranged in another row.

It can be understood that the arrangement of the micro LEDs 31 and the photodiodes 32 of the different colors is not limited to that shown in FIG. 2, and can be adjusted as needed, as long as it is arranged in a 2 × 2 matrix. In addition, in other embodiments of the present invention, each of the pixel units 30 is not limited to those containing the three colors described above. The micro LED 31 may include a micro LED 31 that emits light of other colors.

3 is a schematic plan view showing the arrangement of a plurality of pixel units of a micro LED touch display panel according to another embodiment of the present invention. As shown in FIG. 3, the plurality of pixel units 30 are arranged in a matrix. Each pixel unit 30 includes a red micro LED 311, a green micro LED 312, a blue micro LED 313, and a photodiode 32. Each pixel unit 30 is a photodiode 32, a red micro LED 311, a green micro LED 312, and a blue micro LED 313 in a row. The plurality of pixel units 30 are a row of one photodiode 32, one red micro LED 311, one green micro LED 312, and one blue micro LED 313 alternately and periodically arranged. The plurality of pixel units 30 are an array of photodiodes 32, an array of red micro LEDs 311, an array of green micro LEDs 312, and an array of blue micro LEDs 313. It can be understood that the arrangement of the micro LEDs 31 and the photodiodes 32 of different colors in each pixel unit 30 is not limited to that shown in FIG. 3, and can be adjusted as needed, as long as it is arranged in a row.

In addition, one red micro LED 311, one green micro LED 312, one blue micro LED 313, and one photodiode 322 in each pixel unit 30 may also be arranged in a row. Specifically, the arrangement of one red micro LED 311, one green micro LED 312, one blue micro LED 313, and one photodiode 32 in each pixel unit 30 is arranged in a row. In a column of the plurality of pixel units 30, a red micro LED 311, a green micro LED 312, a blue micro LED 313, and a photodiode 32 are alternately and periodically arranged. The plurality of pixel units 30 are a row of red micro LEDs 311, a row of green micro LEDs 312, a row of blue micro LEDs 313, and a row of photodiodes 32 alternately and periodically arranged. Similarly, the arrangement of the micro LEDs 31 and the photodiodes 32 of different colors in each pixel unit 30 is not limited to this, and can be adjusted as needed, as long as it is arranged in a row.

FIG. 4 is an equivalent circuit diagram of a touch unit of a micro LED touch display panel according to a preferred embodiment of the present invention. As shown in FIG. 4, the plurality of photodiodes 32 of at least two adjacent pixel units 30 constitute a touch unit 300, and the plurality of photodiodes 32 in the touch unit 300 are arranged in multiple rows and columns. cloth. Preferably, the pixel unit 20 corresponding to the plurality of photodiodes 32 in each touch unit 300 forms a rectangle with a side length of about 3 to 5 mm. Specifically, the cathode of each of the photodiodes 32 in the touch unit 300 is grounded, and the anodes of the plurality of photodiodes 32 in the same row are electrically connected (parallel) through the first lead 33, and the plurals of different rows are The anode of the photodiode 32 is electrically connected to the same voltage signal through a second lead 34, so that the photodiodes 32 in the same touch unit 300 are connected in parallel. Wherein, the voltage signal is a voltage signal -V _on-s of a negative potential element.

FIG. 5 is another equivalent circuit diagram of a touch unit of a micro LED touch display panel according to a preferred embodiment of the present invention. As shown in FIG. 5, the plurality of photodiodes 32 of at least two pixel units 30 adjacent to each other constitute a touch unit 300. The plurality of photodiodes 32 in the touch unit 300 are arranged in multiple rows and columns. cloth. Preferably, the pixel unit 20 corresponding to the plurality of photodiodes 32 in each touch unit 300 forms a rectangle with a side length of about 3 to 5 mm. Specifically, the anode of each of the photodiodes 32 in the touch unit 300 is grounded, and the cathodes of the plurality of photodiodes 32 in the same row are electrically connected (parallel) through the first lead 33, and the plural numbers of different rows The cathode of the photodiode 32 is electrically connected to the same voltage signal through a second lead 34, so that the photodiodes 32 in the same touch display unit touch unit 300 are connected in parallel. Wherein, the voltage signal is a voltage signal + V _on-s of a positive potential element.

In this embodiment, the micro LED touch display panel 10 further includes a control circuit 400 for applying the voltage signal to the photodiode 32. The control circuit 400 may be an integrated circuit (IC).

As shown in FIG. 4, the cathodes of the plurality of photodiodes 32 in different rows are electrically connected to the control circuit 400 through a second lead 34, and the control circuit 400 is connected to the control circuit 400 through the second lead 34 and a plurality of the first A lead 33 applies a voltage signal of a negative potential element to the anode of each photodiode 32 in the touch unit 300, so that the potential of the anode of each photodiode 32 in the touch unit 300 is lower than that of the photodiode 2. The potential of the cathode of the pole body 33, and further, each of the photodiodes 32 can sense a corresponding light sensing signal according to the light intensity collected above it.

Similarly, as shown in FIG. 5, the cathodes of the plurality of photodiodes 32 in different rows are electrically connected to the control circuit 400 through a second lead 34, and the control circuit 400 is connected to the control circuit 400 through the second lead 34 and a plurality of The first lead 33 applies a positive potential element voltage signal to the cathode of each photodiode 32 in the touch unit 300, so that the potential of the anode of each photodiode 32 in the touch unit 300 is lower than that of the photodiode 32. The potentials of the cathodes of the photodiodes 33, and further, each of the photodiodes 32 can sense a corresponding light-sensing signal according to the light intensity collected above it.

Further, the control circuit 400 is further configured to receive and process a light sensing signal of the photodiode 32. Specifically, the light sensing signals of the plurality of photodiodes 32 in each row of the touch unit 300 shown in FIG. 4 are summarized by the first lead 33 electrically connected to the second lead 34, and then passed through the second lead 34. The lead 34 is received by the control circuit 400 and processed by signals to obtain the coordinates of the touch position. Similarly, the photosensor signals of the plurality of photodiodes 32 in each row of the touch unit 300 shown in FIG. 5 are summarized to the second lead 34 through the first lead 33 electrically connected to the second lead 34, and then passed through the second lead 34. The lead 34 is received by the control circuit 400, and the coordinates of the touch position can be obtained by processing and calculating the difference of the light sensing signals. Specifically, when a finger covers part of the light above the photodiode 32, a difference occurs in the light sensing signal (such as a photocurrent) in the area. The light sensing signal is received by the analog circuit in the control circuit 400 and then borrowed. It is processed by an analog-to-digital converter (ADC), and then the relative position of the touch point is converted by an algorithm.

In this embodiment, the light sensing signal read by the control circuit 400 is the touch unit. The sum of the light-sensing signals of the plurality of photodiodes 32 in 300 avoids the situation that the light-sensing signal cannot be detected when the change of the light-sensing signal is small, and improves the sensitivity of touch point detection.

6 is a sectional view of a micro LED of a micro LED touch display panel according to a preferred embodiment of the present invention. As shown in FIG. 6, the micro LED 31 includes a cathode 314 of a micro LED, a first N-type doped phosphor layer 315, a first active layer 316, and a first P-type doped phosphor. Material layer 317 and anode 318 of the micro LED. The cathode 314 of the micro LED is a transparent conductive layer, and the cathode 314 of the micro LED is electrically connected to the N-type doped phosphor layer 315; the anode 318 of the micro LED is a metal layer, and the micro LED The anode 318 is electrically connected to the P-type doped phosphor layer 317; the first active layer 316 is used to control the light emitting color of the micro LED 31.

As shown in FIG. 6, the micro LED touch display panel further includes an insulating layer 319 provided on the substrate 200. The insulating layer 319 is provided with a plurality of through holes 320 penetrating the insulating layer 319. The micro LED The cathode 314, the first N-type doped phosphor layer 315, the first active layer 316, the first P-type doped phosphor layer 317, and the anode 318 of the micro LED are located Within the plurality of through holes 320.

FIG. 7 is a cross-sectional view of a photodiode of a miniature LED touch display panel according to a preferred embodiment of the present invention. As shown in FIG. 7, the photodiode 32 includes a cathode 321 of a photodiode, a second N-type doped phosphor layer 322, a second active layer 325, and a second P-type. The doped phosphor layer 323 and the anode 324 of the photodiode. The cathode 321 of the photodiode is a transparent conductive layer, and the cathode 321 layer of the photodiode is electrically connected to the second N-type doped phosphor layer 322; the anode of the photodiode 324 is a metal layer, and the anode 324 of the photodiode is electrically connected to the second P-type doped phosphor layer 323; the second active layer 325 is used to control the photodiode 32 Photoelectric performance.

As shown in FIG. 7, the cathode 321 of the photodiode, the second N-type doped phosphor layer 322, the second P-type doped phosphor layer 323, and the second The active layer 325 and the anode 324 of the photodiode are located in the plurality of through holes 320.

The above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or equivalently replaced. Without departing from the spirit and scope of the technical solution of the present invention.

Claims (8)

A micro LED touch display panel includes a plurality of micro LEDs. The plurality of micro LEDs emit light in a forward biased state. The improvement is that the micro LED touch display panel further includes a plurality of photodiodes. The photodiode senses the change of the light intensity under the negative bias state to detect the touch position. The micro LED touch display panel defines a plurality of pixel units, and each pixel unit includes a complex number that emits light of different colors. A micro LED and a photodiode, and adjacent photodiodes of at least two pixel units constitute a touch unit. The micro LED touch display panel further includes a control circuit for receiving And processing the sum of the light sensing signals of all the photodiodes in each touch unit. The micro LED touch display panel according to claim 1, wherein each micro LED includes an anode and a cathode, and the forward bias state means that the potential of the anode of the micro LED is higher than that of the cathode of the micro LED Each photodiode includes an anode and a cathode. The negative bias state means that the potential of the anode of the photodiode is lower than the potential of the cathode of the photodiode. The micro LED touch display panel according to claim 1, wherein the plurality of micro LEDs in each pixel unit includes a red micro LED, a green micro LED, and a blue micro LED. The micro LED touch display panel according to claim 3, wherein the red micro LED, the green micro LED, the blue micro LED, and the photodiode in each pixel unit form 2 × 2 matrix arrangement. The micro LED touch display panel according to claim 3, wherein the red micro LED, the green micro LED, the blue micro LED, and the photodiode in each pixel unit form a line Or line up. The miniature LED touch display panel according to claim 1, wherein the cathode of each photodiode in the touch unit is grounded, and the anode of the plurality of photodiodes in the touch unit is a wire. Electrically connected to the same negative voltage signal. The miniature LED touch display panel according to claim 1, wherein an anode of each photodiode in the touch unit is grounded, and a cathode of the plurality of photodiodes in the touch unit is connected by a wire. Electrically connected to the same positive voltage signal. The micro LED touch display panel according to any one of claims 1 to 7, wherein the control circuit is configured to apply a voltage signal to the photodiode.