# US 2021/0241707 A1 · Display device and liquid crystal display device for adjusting transparency and polarity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0241707 A1 - Document ID: US20210241707A1 - Status: Published application - Kind: A1 - Application number: 17/238,962 - Filed: 2021-04-23 - Published: 2021-08-05 - Earliest claimed: 2018-01-19 - Assignees: Japan Display Inc. - Applicants: Japan Display Inc. - Inventors: Hirofumi KATO - Web page: https://patentgrep.com/patent/US20210241707A1 ## CPC - G09G 3/3614: {Control of polarity reversal in general} - G02B 6/0035: {provided on the surface of the light guide or in the bulk of it} - G02F 1/1334: based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals - G02F 1/134309: {characterised by their geometrical arrangement} - G02F 1/136286: {Wiring, e.g. gate line, drain line} - G02F 1/1368: in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} - G02F 1/137: characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering - G09G 3/3413: {Details of control of colour illumination sources} - G02F 1/1362: Active matrix addressed cells {(G02F1/134336, G02F1/134363 take precedence)} - G02F 2201/121: common or background - G02F 2201/123: pixel - G09G 2310/0235: Field-sequential colour display - G09G 2310/06: Details of flat display driving waveforms - G09G 2320/0209: Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract According to one embodiment, a display device includes a display panel including a display area where first drive areas and second drive areas are alternately disposed, and display function layers which include first display function layers and second display function layers and which are changed to a transparent state and a scattering state, and a control unit. The control unit applies a drive voltage to the first display function layers, in a first field period. The control unit applies the drive voltage to the second display function layers, in a second field period. A polarity of the drive voltage in the first field period is different from a polarity of the drive voltage in the second field period. ## Claims ### Claim at position 1 1-13. (canceled) ### Claim 14 A display device, comprising: a display panel including a plurality of pixels each including a common electrode, a pixel electrode, and a pixel switch for writing a pixel signal in the pixel electrode; and a control circuit that drives the display panel in a first sub-frame period and a second sub-frame period subsequent to the first sub-frame period, wherein the first sub-frame period includes a first polarity in which a first voltage is applied to the common electrode and a second polarity in which a second voltage is applied to the common electrode, the second sub-frame period also includes the first polarity in which the first voltage is applied to the common electrode and the second polarity in which the second voltage is applied to the common electrode, and the first voltage is higher than the second voltage, wherein the control circuit drives the pixel switch for writing to the pixel electrode in the first polarity in the first sub-frame period and writing to the pixel electrode in the first polarity in the second sub-frame period, and further does not write to the pixel electrode in both the second polarity in the first sub frame and the second polarity in the second sub-frame, or the control circuit drives the pixel switch for writing to the pixel electrode in the second polarity in the first sub-frame period and writing to the pixel electrode in the second polarity in the second sub-frame period, and further does not write to the pixel electrode in both the first polarity in the first sub-frame and the first polarity in the second sub-frame. ### Claim 15 (depends on 14) The device of claim 14, further comprising: a light source unit emitting light to the display panel, wherein each of the first sub-frame period and the second sub-frame period includes a writing period and a lighting period after the writing period, and the control circuit drives the pixel switch for writing to the pixel electrode in the writing period, and the light source unit in the lighting period. ### Claim 16 (depends on 14) The device of claim 14, wherein the display panel includes a display area where first drive areas extending in a row direction and second drive areas extending in the row direction are alternately disposed in a columnar direction, in the first drive areas, the control circuit drives the pixel switch for writing to the pixel electrode in the first polarity in the first sub-frame period and writing to the pixel electrode in the second polarity in the second sub-frame period, and in the second drive areas, the control circuit drives the pixel switch for writing to the pixel electrode in the second polarity in the first sub-frame period and writing to the pixel electrode in the first polarity in the second sub-frame period. ### Claim 17 (depends on 16) The device of claim 16, further comprising: a light source unit emitting light to the display panel, wherein each of the first sub-frame period and the second sub-frame period includes a writing period and a lighting period after the writing period, and the control circuit drives the pixel switch for writing to the pixel electrode in the writing period, and the light source unit in the lighting period. ### Claim 18 (depends on 16) The device of claim 16, wherein frame periods include a first frame period, each of the frame periods includes the first sub-frame period and the second sub-frame period, each of the first sub-frame period and the second sub-frame period includes a first field period and a second field period subsequent to the first field period, the control circuit fixes targets to which the first polarity is set to either the first drive areas or the second drive areas in each first field period in the first frame period, the control circuit fixes targets to which the second polarity is set to the other of the first drive areas and the second drive areas in each second field period in the first frame period, and the control circuit replaces the targets to which the first polarity is set in each first field period and the targets to which the second polarity is set in each second field period every time the frame periods are changed. ### Claim 19 (depends on 18) The device of claim 18, wherein each of the frame periods includes a reset period that is a leading period of the frame period, and in the reset period, a state of the first drive areas and the second drive areas is changed to a transparent state. ### Claim 20 (depends on 16) The device of claim 16, wherein frame periods include a first frame period, each of the frame periods includes sub-frame periods including the first sub-frame period and the second sub-frame period, each of the sub-frame periods includes a first field period and a second field period subsequent to the first field period, the control circuit fixes targets to which the first polarity is set to either the first drive areas or the second drive areas in the first field period in the first sub-frame period in the first frame period, the control circuit fixes targets to which the second polarity is set to the other of the first drive areas and the second drive areas in the second field period in the first sub-frame period in the first frame period, and the control circuit replaces the targets to which the first polarity is set in the first field period and the targets to which the second polarity is set in the second field period every time the sub-frame periods are changed. ### Claim 21 (depends on 20) The device of claim 20, wherein each of the frame periods includes a reset period that is a leading period of the frame period, and in the reset period, a state of the first drive areas and the second drive areas is changed to a transparent state. ### Claim 22 (depends on 16) The device of claim 16, wherein the display panel is changed to a transparent state of urging incident light to be transmitted and a scattering state of scattering the incident light. ### Claim 23 (depends on 22) The device of claim 22, further comprising: a light source unit emitting light to the display panel, wherein the display panel includes a display area, a non-display area outside the display area, and a transparent substrate having an end portion located in the non-display area, and the light source unit is located in the non-display area, and opposed to the end portion. ### Claim 24 (depends on 22) The device of claim 22, wherein the display panel includes a liquid crystal layer using reverse mode polymer dispersed liquid crystal. ### Claim 25 (depends on 24) The device of claim 24, further comprising: a light source unit emitting light to the display panel, wherein the display panel includes a display area, a non-display area outside the display area, and a transparent substrate having an end portion located in the non-display area, and the light source unit is located in the non-display area, and opposed to the end portion. ### Claim 26 (depends on 14) The device of claim 14, wherein the display panel includes a liquid crystal layer using a polymer dispersed liquid crystal. ### Claim 27 (depends on 26) The device of claim 26, wherein the polymer dispersed liquid crystal is a reverse mode polymer dispersed liquid crystal.