DISPLAY DEVICES WITH ROTATABLE LIGHT EMITTING DIODES

In one example, a display device may include a liquid crystal panel and a direct type backlight unit having a light emitting diode (LED) package disposed behind the liquid crystal panel. The LED package may include a plurality of LEDs. The plurality of LEDs may have a first orientation towards the liquid crystal panel to provide a first viewing angle. Further, the display device may include a control unit to rotate the LED package to allow the plurality of LEDs to have a second orientation towards the liquid crystal panel to provide a second viewing angle. The second viewing angle may be narrower than the first viewing angle.

BACKGROUND

The emergence and popularity of mobile computing has made electronic devices, due to their compact design and light weight, a staple in today's marketplace. Electronic devices, such as mobile phones, notebooks and tablets, may include a display that outputs information to users. Example display may include a micro-light emitting diode (micro-LED or μLED) display. Micro-LED displays may have arrays of microscopic LEDs forming the individual pixel elements. The users may use the display to view private information, such as private financial information or a confidential email. Because of the increased portability of electronic devices, users can transport and use the electronic devices in public areas where the privacy is minimal.

DETAILED DESCRIPTION

Electronic devices, such as mobile phones, notebooks and tablets, may include a display that outputs information to users. The users may use the display to view private information, such as private financial information or a confidential email. Often, the user may be in public, such as when the user is sitting in a waiting room, standing in line, or riding on public transportation. In such situations, other people may view the display of the users electronic device, particularly when the users electronic device includes a display viewable from a wide variety of angles. In some examples, the viewing angle may be controlled by reducing brightness of a display and increasing power for light emitting diode (LED) backlighting. However, this may increase power consumption and impact brightness of the display. In some other examples, detachable privacy screens may be used at displays to restrict propagation direction of light emitted from the displays. In such cases, the use of privacy screens may inhibit or reduce functionality of a touch screen associated with the displays.

Examples described herein may control different degree of privacy modes on, a display device by rotating an LED to narrow down a viewing angle. Example display device may include a micro-LED (μ-LED) display, a mini-LED display, a micro-electro-mechanical systems (MEMS) display, or the like. For example, micro-LED display, also known as m-LED or μ-LED, is an emerging flat panel display technology having arrays of microscopic LEDs that form the individual pixel elements. Example display device may include a plurality of LED packages. Each LED package may include at least one micro-LED or mini-LED. In other examples, each LED package may include an LED of a MEMS-type.

In one example, the display device may include a liquid crystal panel and a direct type backlight unit having an LED package disposed behind the liquid crystal panel. The LED package may include a plurality of LEDs, the plurality of LEDs is to have a first orientation towards the liquid crystal panel to provide a wide viewing angle. Further, the display device may include a control unit to rotate the LED package to allow the plurality of LEDs to have a second orientation towards the liquid crystal panel to provide a narrow viewing angle.

Examples described herein may provide a switchable privacy control on the display device to control the viewing angle and protect a display from prying eyes. In this case, the LED packages can be rotated to change the light direction when the user selects the privacy mode. Thus, sensitive data, such as information associated with insurance, banking, finance, human resources, trade, examination rooms, medical personnel, security applications, or the like, can be protected from the prying eyes.

Examples described herein may provide a 2-way or a 4-way privacy control (i.e., a horizontal viewing angle control and/or a vertical viewing angle control) based on an arrangement of the LED packages on the direct type backlight unit. Examples described herein may also provide a multi-mode privacy control. For example, a degree of privacy on the display can be controlled by rotating the LED packages to multiple orientations corresponding to multiple privacy modes. Examples described herein may also provide a high brightness privacy control solution for the displays. Thus, examples described herein may provide the multi-mode privacy control with efficient power consumption and without impacting the brightness of the display.

Referring to the figures,FIG. 1Ais a cross-sectional view of an example display device100, depicting an LED package106including a plurality of LEDs108having, a first orientation towards a liquid crystal panel102. Display device100may include an external display to a computing device, an internal display to the computing device, or any combination thereof. Example display device100may include a touchscreen display.

Example display device100may include liquid crystal panel102. Further, display device100may include a direct type backlight unit104including LED package106disposed behind liquid crystal panel102. In some examples, display device100may include a plurality of LED packages, for instance, integrated to a circuit board of display device100. Each LED package may include a plurality of LEDs. In one example, the LED packages may be arranged in columns and/or rows. In another example, the LED packages may be uniformly arranged.

Direct type backlight unit104may indicate that LEDs108are arranged at back of liquid crystal panel102as backlight. In direct type backlight unit104, the plurality of LED packages may be arranged at the back of liquid crystal panel102, for instance in vertical columns, where each LED package106may include multiple LEDs108connected in series.

In one example, plurality of LEDs108may have a first orientation towards liquid crystal panel102to provide a first viewing angle (e.g., as shown by arrow112ofFIG. 1A). For example, liquid crystal panel102may be disposed above LED package106such that the light emitted by LEDs108may exit direct type backlight unit104and transmit through liquid crystal panel102to reach the user's eyes. In this example, plurality of LEDs108may have the first orientation towards and parallel to liquid crystal panel102.

For example, display device100may output data via an array of pixel elements. Each LED package106may include at least one μ-LED pixel that can be driven to emit light. A pixel may refer to a component of display device100that can be used to build the image. For example, each μ-LED pixel may include a red pixel, a green pixel, a blue pixel, or any combination thereof, which can be independently controlled to produce a range of colors.

Furthermore, display device100may include a control unit110coupled to LED package106. In some examples, control unit110may be implemented as engines or modules comprising any combination of hardware and programming to implement the functionalities described herein.

During operation, control unit110may rotate LED package106to allow plurality of LEDs108to have a second orientation towards liquid crystal panel102to provide a second viewing angle (e.g., as shown by arrow156ofFIG. 1B). In this example, the second viewing angle may be narrower than the first viewing angle.FIG. 1Bis a cross-sectional view of example display device100ofFIG. 1A, depicting plurality of LEDs108having the second orientation towards liquid crystal panel102. For example, similarly named elements ofFIG. 1Bmay be similar in structure and/or function to elements described with respect toFIG. 1A.

As shown inFIG. 1B, control unit110may rotate LED package106at an angle in a range of 0 to 75 degrees to change the light direction of LEDs108to provide the second viewing angle. In one example, display device100may include a driving unit152coupled to LED package106to rotate LED package106. Further, display device100may include an electromagnetic switch154to activate or drive driving unit152. An example mechanism to rotate LED package106is shown inFIGS. 1C and 1D.FIGS. 1A and 18describe driving unit152as being coupled to LED package106, however, driving unit152can be coupled to an LED or a plurality of LED packages such that driving unit152can rotate the LED, an LED package having a plurality of LEDs, or the plurality of LED packages to provide the second viewing angle.

FIG. 1Cis a schematic diagram illustrating example LED package106ofFIG. 1A. In one example, LED package106may include an LED bar158. In this example, plurality of LEDs108may be disposed on LED bar158. Further, LED package106may include driving unit152to drive LED bar158to rotate.

In one example, driving unit152may include an electric motor160. One end of LED bar158may be pivoted to a fixed support162and other end of LED bar158may be connected to an output shaft of electric motor160. For example, fixed support162may be connected to a backplane (e.g., backplane164as shown inFIG. 10). Electromagnetic switch154may energize and de-energize electric motor160to rotate LED bar158. Control unit110may selectively energize and de-energize electric motor160by turning on and off electromagnetic switch154. In other examples, electric motor160may be a reciprocating motor, and the rotating range of the output shaft may be about 0-75 degrees. Using such a solution, the control logic of electric motor160may be relatively simple and the rotation position of LED bar158may be precisely controlled.

FIG. 1Dis a schematic diagram illustrating a top view of example direct type backlight unit104ofFIG. 1A, depicting example LED package106(e.g., LED bar158) in a narrow viewing angle. As shown inFIG. 1D, direct type backlight unit104may include a backplane164. Direct type backlight unit104may also include a plurality of LED bars158each including plurality of LEDs108. Backplane164may have a holding space, and plurality of LED bars158(e.g., LED packages106) may be disposed inside the holding space of backplane164. Liquid crystal panel102may be disposed above plurality of LED bars158. Each LED bar158can be rotatable to allow plurality of LEDs108to have the first orientation and the second orientation toward liquid crystal panel102. In the example shown inFIG. 1D, LED bar158may be rotated (e.g., in a direction, as shown by arrow166) to the second orientation toward liquid crystal panel102to provide the narrow viewing angle in a privacy mode.

The privacy mode may be activated explicitly by a user or may be activated in response to a privacy mode trigger event. In one example, touchscreen may be used to detect a gesture to activate and/or de-activate the privacy mode. In another example, the privacy mode may be activated and/or deactivated via a keyboard and/or keypad. In yet another example, microphone in display device100may be used to detect a spoken command to activate the privacy mode. In yet another example, the privacy mode or the normal mode may be manually selected by a user. In yet another example, the privacy mode or the normal mode may be automatically detected based on user gestures through at least one sensor disposed in display device100. Example sensor may include a camera.

Thus, LED package106may be rotatable to the first and second orientations to switch the viewing angle between a wide viewing angle and a narrow viewing angle. The wide viewing angle may refer to a maximum angle at which information/content displayed on display device100can be viewed. The wide viewing angle may be greater than the narrow viewing angle. During privacy mode of operation, the viewing angle (e.g., range of viewing the sensitive information on display device100) may need to be restricted to prevent other users from viewing the display of display device100. In this case, the viewing angle of the display may be switched to the narrow viewing angle to enable privacy of the information/content displayed on the display. During normal mode of operation, the viewing angle of the display may be switched to the wide viewing angle.

FIG. 2Ais a cross-sectional view of an example display device200, depicting a control unit214to rotate an LED208to control a viewing angle. Example display device200may include a mobile communication device, such as a smart phone, a laptop, a tablet, a convertible device that can be used in both laptop and tablet modes, a media playing device, a portable gaming system, and/or any other type of portable computer device with a display screen that displays visual data. Example display device200may include a liquid crystal display (LCD), light emitting diode (LED) display, μ-LED display, mini-LED display, MEMS display, or other displays that includes arrays of LED packages (e.g., LEDs). A μ-LED or mini-LED may be considered as a type of LED. Display device200may be equipped with other components such as a camera, audio/video devices, and the like, depending on the functions of display device200.

Display device200may include a liquid crystal panel202including a liquid crystal layer210. Further, display device200may include a direct type backlight unit204. In one example, direct type backlight unit204may include a backplane206and LED208disposed on backplane206to provide light towards liquid crystal panel202(i.e., to radiate the back light directly to liquid crystal panel202). In some examples, backplane206may be equipped with arrays of spaced LEDs, each LED208may include a red μ-LED, a green μ-LED, a blue μ-LED, or any combination thereof. LED208may have a first orientation towards liquid crystal panel202to provide a first viewing angle. In one example, LED208may be disposed on an LED bar that is arranged vertically on direct type backlight unit204.

Further, display device200may include a driving unit212coupled to LED208. Example driving unit212may include at least one electric motor. Furthermore, display device200may include control unit214coupled to driving unit212. In some examples, control unit214may be implemented as engines or modules comprising any combination of hardware and programming to implement the functionalities described herein. In one example, control unit214can be implemented as a part of display device200, for instance, in case of tablet computers. In another example, control unit214can be implemented as a part of a base housing (e.g., that houses battery, touchpad, keyboard and the like) of display device200and communicatively connected to a display housing of display device200, for instance, in case of notebook computers.

During operation, control unit214may rotate LED208, via driving unit212to have a second orientation towards liquid crystal panel202to provide a second viewing angle (e.g., as shown by arrow260ofFIG. 25). The second viewing angle may be narrower than the first viewing angle. In one example, control unit214may control LED208or the LED bar such that LED208or the LED bar is to rotate towards a vertical center viewing portion of liquid crystal panel202to provide the second viewing angle.

For example, the light emitted from LED208may exit direct type backlight unit204and transmit directly through liquid crystal panel202at a first angle in the first orientation. Further, the light emitted from LED208may exit direct type backlight unit204and transmit directly through liquid crystal panel202at a second angle in the second orientation. Also, control unit214may control a degree of privacy on liquid crystal panel202by rotating LED208to multiple positions corresponding to multiple privacy modes. In this case, each position may transmit the light directly through liquid crystal panel202at a different angle. Each privacy mode may have a viewing angle that is different from the other privacy modes.

FIG. 2Bis across-sectional view of example display device200ofFIG. 2A, depicting additional features. For example, similarly named elements ofFIG. 2Bmay be similar in structure and/or function to elements described with respect toFIG. 2A. As shown inFIG. 2B, liquid crystal panel202may include a thin-film transistor (TFT) substrate254and a color filter (CF) substrate252arranged above TFT substrate254. In one example, liquid crystal layer210may be arranged between TFT substrate254and CF substrate252.

Also, display device200may include a ring of adhesive sealant258may surround liquid crystal layer210. In one example, adhesive sealant258may retain liquid crystal material between CF substrate252and TFT substrate254. Also, in the example shown inFIG. 2B, an integrated circuit256may be mounted to TFT substrate254.

Display device200may also include other components associated with TFT substrate254, CF substrate252, and liquid crystal layer210. For example, CF substrate252may include a black matrix, a color filter alternating red, green, and blue (RGB) with the black matrix therebetween, and a common electrode formed on the black matrix and the color filter. The common electrode is made of transparent conductive material like ITO (indium Tin Oxide) or IZO (Indium Zinc Oxide). Further, display device200may include the common electrode and a pixel electrode formed at the inner surfaces facing CF substrate252and TFT substrate254respectively in order to apply an electric field to liquid crystal layer210. The liquid crystal panel202may also include a polarizer disposed on a rear of TFT substrate254and a front of CF substrate252for polarizing light transmitted from liquid crystal panel202.

Even thoughFIGS. 1 and 2describe LED packages that are being arranged on the direct type backlight unit in vertical columns, LED packages can also be arranged in horizontal rows or a combination of rows and columns. For example, examples described herein may provide a 2-way or a 4-way privacy control (i.e., a horizontal viewing, angle control and/or a vertical viewing angle control) based on an arrangement of the LED packages on the direct type backlight unit.

Control units110and214may include, for example, hardware devices including electronic circuitry for implementing the functionalities described herein. In addition or as an alternative, control units110and214may be implemented as a series of instructions encoded on a machine-readable storage medium of device (e.g., display device100or200) and executable by processor. In examples described herein, the processor may include, for example, one processor or multiple processors included in a single device or distributed across multiple devices. It should be noted that, in some examples, some modules are implemented as hardware devices, while other modules are implemented as executable instructions.

FIG. 3depicts a block diagram of an example computing device300including a machine-readable storage medium304, storing instructions to implement a privacy mode of a display. Computing device300may include a processor302and a machine-readable storage medium304communicatively coupled through a system bus. Processor302may be any type of central processing unit (CPU), microprocessor, or processing logic that interprets and executes machine-readable instructions stored in machine-readable storage medium304. Machine-readable storage medium304may be a random-access memory (RAM) or another type of dynamic storage device that may store information and machine-readable instructions that may be executed by processor302. For example, machine-readable storage medium304may be synchronous DRAM (SDRAM), double data rate (DDR), rarnbus DRAM (RDRAM), rambus RAM, etc., or storage memory media such as a floppy disk, a hard disk, a CD-ROM, a DVD, a pen drive, and the like. In an example, machine-readable storage medium304may be a non-transitory machine-readable medium. In an example, machine-readable storage medium304may be remote but accessible to computing device300.

Machine-readable storage medium304may store instructions306and308. In an example, instructions306and308may be executed by processor302to control a viewing angle of the display when the privacy mode is activated or deactivated. Instructions306may be executed by processor302to detect an activation of a privacy mode of a display of the computing device. The display may include an LED package having an orientation towards a liquid crystal panel to provide a first viewing angle of the display in a normal mode.

Instructions308may be executed by processor302to rotate the LED package to a first angle in a range of 0 to 75 degrees to change light direction of the LED package to provide a second viewing angle of the display, in response to detecting the activation of the privacy mode. The second viewing angle may be narrower than the first viewing angle.

In one example, the LED package may include an LED. The LED may be at the orientation towards and parallel to the liquid crystal panel to provide the first viewing angle. Further, the LED may be rotated to the first angle towards a vertical center viewing portion of the liquid crystal panel to provide the second viewing angle.

In other examples, machine-readable storage medium304may include instructions to receive an input to enable a second privacy mode of the display and rotate the LED package to a second angle in the range of 0 to 75 degrees to change the light direction of the LED package to provide a third viewing angle of the display. The third viewing angle may be narrower than the second viewing angle. In this example, the second angle may be greater than the first angle.

It may be noted that the above-described examples of the present solution are for the purpose of illustration only. Although the solution has been described in conjunction with a specific implementation thereof, numerous modifications may be possible without materially departing from the teachings and advantages of the subject matter described herein. Other substitutions, modifications and changes may be made without departing from the spirit of the present solution. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where a least some of such features and/or steps are mutually exclusive.

The terms “include,” “have,” and variations thereof, as used herein, have the same meaning as the term “comprise” or appropriate variation thereof. Furthermore, the term “based on”, as used herein, means “based at least in part on.” Thus, a feature that is described as based on some stimulus can be based on the stimulus or a combination of stimuli including the stimulus.