# US 10,372,253 B2 · Touch display device and backlight unit thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,372,253 B2 - Document ID: US10372253B2 - Status: Granted - Kind: B2 - Application number: 15/225,635 - Filed: 2016-08-01 - Published: 2017-10-05 - Granted: 2019-08-06 - Earliest claimed: 2016-04-04 - Assignees: LG Display Co., Ltd. - Applicants: LG Display Co., Ltd. - Inventors: Mira Kim - Web page: https://patentgrep.com/patent/US10372253B2 ## CPC - G06F 3/044: by capacitive means - G06F 3/04144: {using an array of force sensing means (position sensing using the local deformation of sensor cells G06F3/0447)} - G06F 3/0445: {using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer} - G06F 3/0447: {Position sensing using the local deformation of sensor cells} - G06F 3/0412: {Digitisers structurally integrated in a display} - G06F 2203/04105: Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position - G06F 2203/04106: Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Discussed is a touch display device able to sense a touch position of a user touch and an amount of user touching force. A case disposed below the backlight unit is used as a touching force sensing electrode, enabling a touch display device to sense touch force using the case. A gap is formed by an open area in the bottom cover of the backlight unit, enabling the user touching force to be sensed without an increase in the thickness of the touch display device. ## Claims ### Claim 1 A touch display device comprising: a display panel having a plurality of electrodes including a first electrode and a second electrode disposed therein; a light source device disposed below the display panel and emitting light to the display panel; a bottom cover disposed on sides of and below a structure to accommodate the light source device; and a case disposed below the bottom cover, and the case including an electrically conductive material, wherein the bottom cover has an open area in a portion thereof corresponding to a bottom surface of the light source device, wherein the open area of the bottom cover forms a gap between the bottom surface of the light sources device and a top surface of the case, wherein display driving voltages for displaying images are applied to the plurality of electrodes during a display mode period of the touch display device, wherein a first electrode driving signal is applied to the plurality of electrodes during a touch driving period of the touch display device, wherein a second electrode driving signal is applied to the case during a force driving period of the touch display device, and wherein the second electrode is a part of the case. ### Claim 2 (depends on 1) The touch display device according to claim 1, wherein the second electrode driving signal applied to the case disposed below the bottom cover comprises a ground voltage signal. ### Claim 3 (depends on 1) The touch display device according to claim 1, wherein the open area includes a plurality of open areas formed in the portion of the bottom cover corresponding to the bottom surface of the light source device. ### Claim 4 (depends on 1) The touch display device according to claim 1, wherein a gap is present between a bottom surface of the display panel and a top surface of the light source device. ### Claim 5 (depends on 1) The touch display device according to claim 1, further comprising a bonding material disposed on outer margins of the display panel and outer margins of the bottom cover to connect the display panel and the bottom cover to each other. ### Claim 6 (depends on 5) The touch display device according to claim 5, wherein some of portions of the bonding material bonded to the outer margins of the display panel and the outer margins of the bottom cover are stepped. ### Claim 7 (depends on 1) The touch display device according to claim 1, wherein the bottom cover includes an electrically conductive material. ### Claim 8 A touch display device comprising: a plurality of first electrodes disposed in a display panel; a second electrode disposed outside of the display panel and spaced apart from the plurality of first electrodes; and a bottom cover disposed below the plurality of first electrodes, accommodating a structure disposed below the display panel, and having an open area in a portion thereof corresponding to a bottom surface of the structure, wherein the open area of the bottom cover forms a gap between the bottom surface of the structure disposed below the display panel and a top surface of the second electrode, wherein display driving voltages for displaying images are applied to the plurality of first electrodes during a display mode period of the touch display device, wherein a first electrode driving signal is applied to the plurality of first electrodes during a touch driving period of the touch display device, wherein a second electrode driving signal is applied to the second electrode during a force driving period of the touch display device, and wherein the second electrode is a part of the bottom cover. ### Claim 9 (depends on 8) The touch display device according to claim 8, wherein the open area includes a plurality of open areas formed in the portion of the bottom cover corresponding to the bottom surface of the structure. ### Claim 10 (depends on 9) The touch display device according to claim 9, further comprising a case disposed below the bottom cover, wherein the second electrode comprises a conductive layer disposed on the case and positioned within the plurality of open areas formed in the bottom of the bottom cover, wherein the conductive layer includes a pattern of electrodes that correspond to the plurality of open areas. ### Claim 11 (depends on 8) The touch display device according to claim 8, wherein a gap is present between a bottom surface of the display panel and a top surface of the structure disposed below the display panel. ### Claim 12 (depends on 8) The touch display device according to claim 8, further comprising a bonding material disposed on outer margins of the display panel and outer margins of the bottom cover to connect the display panel and the bottom cover to each other. ### Claim 13 (depends on 12) The touch display device according to claim 12, wherein some of portions of the bonding material bonded to the outer margins of the display panel and the outer margins of the bottom cover are stepped. ### Claim 14 (depends on 8) The touch display device according to claim 8, wherein the second electrode driving signal applied to the second electrode comprises a ground voltage signal. ### Claim 15 (depends on 8) The touch display device according to claim 8, wherein the second electrode comprises an electrically conductive case disposed below the bottom cover. ### Claim 16 (depends on 8) The touch display device according to claim 8, further comprising a case disposed below the bottom cover, wherein the second electrode comprises a conductive layer disposed on the case and positioned within the open area formed in the bottom of the bottom cover. ### Claim 17 (depends on 16) The touch display device according to claim 16, wherein the open area of the bottom cover forms a gap between the bottom surface of the structure disposed below the display panel and a top surface of the conductive layer. ### Claim 18 A touch display device comprising: a plurality of first electrodes disposed in a display panel; a second electrode disposed outside of the display panel and spaced apart from the plurality of first electrodes; a bottom cover disposed below the plurality of first electrodes, accommodating a structure disposed below the display panel, and having an open area in a portion thereof corresponding to a bottom surface of the structure, wherein the open area includes a plurality of open areas formed in the portion of the bottom cover corresponding to the bottom surface of the structure; and a case disposed below the bottom cover, wherein the second electrode comprises a conductive layer disposed on the case and positioned within the plurality of open areas formed in the bottom of the bottom cover, wherein the conductive layer includes a pattern of electrodes that correspond to the plurality of open areas, wherein the open area of the bottom cover forms a gap between the bottom surface of the structure disposed below the display panel and a top surface of the second electrode.