WO2012101315A1

WO2012101315A1 - Display module providing animation effect

Info

Publication number: WO2012101315A1
Application number: PCT/FI2011/050072
Authority: WO
Inventors: Mika Juhani ANTILA
Original assignee: Nokia Corporation
Priority date: 2011-01-28
Filing date: 2011-01-28
Publication date: 2012-08-02

Abstract

A method is presented for frame buffer animation using bit plane extraction. The method is for producing a power efficient idle mode or power saving mode animation such as a screen saver in a portable device. A display module includes a display panel having a plurality of pixels, and a driver configured to supply an image to the display panel, comprising an image memory, configured to store an image of an n-bit word (265) for each pixel. The display module further includes a timing controller and at least one memory including computer program code. At least two images each with m-bit word (225, 226) for each pixel are stored to the n-bit word (265) in the image memory, wherein n is greater than or equal to 2m. The driver is controlled to sequentially supply the images with m-bit word for each pixel to the display panel, to provide an animation effect.

Description

DISPLAY MODULE PROVIDING ANIMATION EFFECT

TECHNICAL FIELD

The present invention relates generally to display modules or apparatuses comprising display modules and, more specifically, to provide an animation effect. BACKGROUND ART

Various flat panel displays have been developed for presenting visual information to a user. Especially for mobile apparatuses, power consumption may be a critical issue. At the same time, users of the mobile apparatuses prefer images and animations being played on the display even when not using the apparatus, in idle mode.

Extensive usage of mobile apparatuses together with power-consuming idle mode display functionalities means, that the display of the mobile apparatus is active for long periods of time, which consumes a large share of the mobile apparatus power resources, typically batteries. Furthermore, the processor of the apparatus engine may be needed. Thus, a user may have to recharge the mobile apparatus battery inconveniently often, and a battery charger may not always be available when needed.

A user has always the possibility of reducing idle mode functionalities for e.g . display animations, but this may not be what many users would do if they are given a free choice. Having an active animation or sequence of images run by the engine processor during the idle mode may drain a battery of an electron ic apparatus. SUMMARY According to a first example aspect of the invention there is provided a display module comprising:

a display panel having a plurality of pixels;

a driver configured to supply images to the display panel, the driver comprising an image memory, and being configured to store an image with an n-bit word for each pixel;

a timing controller and at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the timing controller, cause the display module at least to:

store at least two images each with an m-bit word for each pixel to the image memory as the n-bit word for each pixel, wherein n is greater than or equal to 2m; and

control the driver to sequentially supply the images with the m-bit word for each pixel to the display panel, to provide an animation effect. The display panel may comprise an organic light emitting diode panel . M most significant bits of the n-bit word may relate to the first image of the m-bit word for each pixel and following m bits of the n-bit word may relate to the second image of the m-bit word for each pixel. Furthermore, the driver may comprise a scan driver configured to supply a scan signal to the display panel, and a data driver configured to supply a data signal to the display panel. The timing controller may generate a data control signal to control the data signal and a scan control signal to control the scan driver.

The image memory may comprise 8-bit word for each pixel, wherein the image memory may comprises eight images with 1 -bit word for each pixel. The eight images with the 1 -bit word for each pixel may be stored as an 8-bit word for said pixel. The pixel may comprise at least one of the following sub-pixels: red, green and blue. The driver may be sequentially controlled to supply the images with the m-bit word for each pixel with a speed greater than two image frames per second. The display module may be further caused to compress the m-bit word for each pixel in the n- bit word in the image memory.

The display module may be further caused to scale the supplied images each with the m-bit word for each pixel as 2x2 pixel blocks. Furthermore, an upper limit for simultaneously active pixels may be defined.

According to a second example aspect of the invention there is provided an apparatus comprising a display module of the first aspect;

at least one apparatus processor and at least one apparatus memory including computer program code, the at least one apparatus memory and the computer program code being configured to, with the at least one apparatus processor, cause the apparatus at least to:

transfer, over a communication interface, the at least two images each with the m-bit word for each pixel from the apparatus memory to the n-bit word for each pixel in the image memory of the driver for storing.

According to a third example aspect of the invention there is provided a method comprising:

providing at least two images each with an m-bit word for each pixel to an n-bit word for each pixel in the image memory of a driver in a display module;

storing the at least two images each with the m-bit word for each pixel to the image memory as the n-bit word for each pixel, wherein n is greater than or equal to 2m; and

controlling the driver to sequentially supply the images with the m-bit word for each pixel to a display panel of the display module for providing an animation effect.

According to a fourth example aspect there is provided a computer program comprising computer executable program code configured to cause an apparatus to perform, on executing the program code, a method according to the third aspect.

According to a fifth example aspect there is provided a memory medium carrying the computer program of the fourth example aspect.

Any foregoing memory medium may comprise digital data storage such as a data disc or diskette, optical storage, magnetic storage, holographic storage, opto- magnetic storage, phase-change memory, resistive random access memory, magnetic random access memory, solid-electrolyte memory, ferroelectric random access memory, organic memory or polymer memory. The memory medium may be formed into a device without other substantial functions than storing memory or it may be formed as part of a device with other functions, including but not limited to a memory of a computer, a chip set, and a sub assembly of an electronic device.

Different non-binding example aspects and embodiments of the present invention have been illustrated in the foregoing. The above embodiments are used merely to explain selected aspects or steps that may be utilized in implementations of the present invention. Some embodiments may be presented only with reference to certain example aspects of the invention. It should be appreciated that corresponding embodiments may apply to other example aspects as well.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 shows some details of the display panel in accordance with an example embodiment of the invention;

Fig. 2a shows a schematic drawing of a first display mode in an apparatus in accordance with an example embodiment of the invention;

Fig. 2b shows a schematic drawing of a second display mode in an apparatus in accordance with an example embodiment of the invention;

Fig. 2c shows a schematic drawing of a second display mode in an apparatus in accordance with another example embodiment of the invention;

Fig. 3 shows an example block diagram of an image processing pipeline in which various embodiments of the invention may be applied;

Fig. 4 shows an example block d iagram of an apparatus in which various example embodiments of the invention may be applied; and

Fig. 5 shows a flow chart showing operations in an apparatus in accordance with an example embodiment of the invention.

DETAILED DESCRIPTION

In the following description, like numbers denote like elements. Fig. 1 shows some details of the display panel 1 10 in accordance with an example embodiment of the invention. The display panel 1 10 may comprise picture elements or pixels 120.

The more pixels 120 are used to represent an image, the closer the result can resemble the original. The number of pixels in an image may sometimes be called the resolution, though resolution has a more specific definition. Pixel counts may be expressed as a single number, as in a "three-megapixel" digital camera, which has a nominal three million pixels. Alternatively, the resolution may be expressed as a pair of numbers, as in a "640 by 480 display", which has 640 pixels from side to side and 480 from top to bottom. The total number of pixels is thus 640 480 = 307,200 pixels or 0.3 megapixels. Alternatively, the resolution may also be expressed as RGB pixels that take into account the depth of sub-pixels R (red), G (green) and B (blue). If three sub-pixels (R,G,B) are used, the resolution may be expressed for above mentioned display as 640 x 480 x 3 pixels. Sometimes resolution information of 640 x 3 x 480 or 1 920 x 480 pixels is also used . In following description, term pixel may be also used to mean sub-pixel and term sub-pixel to mean pixel. Many display and image-acquisition systems are, for various reasons, not capable of displaying or sensing the different color channels at the same site. Therefore, the pixel grid is divided into single-color regions that contribute to the displayed or sensed color when viewed at a distance. In some displays, such as liquid crystal display (LCD), light emitting diode (LED), and plasma displays, these single-color regions are separately addressable elements, which have come to be known as sub-pixels 131 -133. For example, display may divide each pixel 120 into three sub-pixels 131 -1 33. Sub-pixels 131 -133 are often referred to as pixels 120, as they are the basic addressable elements.

In the method of and apparatus for displaying a multicolor image in an example embodiment of the invention, the image has a first density of image pixels 120. Each image pixel 120 may comprise at least first and second image sub-pixels 131 -133 having first and second different colors, respectively. A display panel 1 10 is provided having a density of display pixels which is less than or equal to the density of pixels in the image. Each display pixel 120 comprises at least first and second spatially offset display sub-pixels 131 -133 capable of displaying the first and second colors, respectively. In an example embodiment of the invention, each pixel 120 may consist of a red sub-pixel 1 31 , a blue sub-pixel 1 32, and a green sub-pixel 1 33 arranged in a triangular format. However, the number of sub-pixels may change and the shape of the format may be different to triangular. In an alternative arrangement, each pixel 120 may consist of one red sub-pixel 131 , one blue sub-pixel 132, and two green sub-pixels 1 33 arranged in a two-by-two square, for example. In a still further alternative arrangement, each pixel 120 may consist of one red sub-pixel 131 , one blue sub-pixel 132, and one green sub-pixel 133 arranged in a square, for example. Fig. 2a shows a schematic drawing of a first display mode in an apparatus in accordance with an example embodiment of the invention. A display driver (not shown) may have 8 bit per sub-pixel 230 frame memory for showing a pixel 210 of a first mode image on a screen. The 8 bit word 250 may correspond to a single sub-pixel 230 of the displayed first mode image information comprising bits from the most significant bit (MSB) 1_0 to the least significant bit (LSB) 1_7 . The 8 bit word 250 may comprise information of the depth of color, for example. 8 bit words for three sub-pixels 230 may be stored as a 24 bit word to the display driver memory for each pixel of the displayed image frame.

Fig. 2b shows a schematic drawing of a second display mode in an apparatus in accordance with an example embodiment of the invention. When the apparatus is not actively operated by a user, or the apparatus is locked by the user, a power- saving mode may be provided. In such a mode, an engine comprising the main processor of the apparatus may be switched to a power-saving mode. At the same time, the d isplay module may be switched to a power-saving mode. Before switching to the power-saving mode, single image information may be transferred from the engine to the display driver of the display module. Such image may comprise also information like a clock, date or received messages, for example. However, users of the mobile apparatuses wou ld prefer having also l ive animations instead of still images. At the same time, the power consumption of the apparatus should not remarkably increase. Providing live animations using the engine of the apparatus would be one option. In such an option, the apparatus engine would update the image information on the display panel in certain frame speed to produce animation effect. However, running the an imation effect from the eng ine of the apparatus consumes remarkable amount of power, which is not preferred in the power-saving mode.

In an example embodiment of the invention, the power-saving mode may be implemented by storing image information for each sub-pixel to a memory of a display driver included in the display module. For example, only most significant bit (MSB) 1_0 of the power-saving mode sub-pixel word 260 may be used for a still image to be shown in the display panel in power-saving mode. In another example embodiment of the invention, all 8 bits of the word 260 for the sub-pixel may be used. A first bit 1_0 of the word 260 may correspond to a pixel 220 and a sub-pixel 240 of a first image IMG1 . A second bit 2_0 of the word 260 may correspond to a pixel and a sub-pixel of a second image IMG2, and so on. Last bit 8_0 may correspond to a pixel 221 and a sub-pixel 241 of an eighth image IMG8. Altogether eight images IMG1 - IMG8 may be stored to the memory of the display driver when each sub-pixel 240, 241 of the image IMG1 - IMG8 may have the 8-bit word 260 representing the eight images.

In an example embodiment of the invention, the engine of the apparatus may be needed only when transferring the image data to the memory of the driver. In the power-saving mode, an an imation may be provided on the d isplay panel by running the 8 images sequentially on the display panel. Displaying of the images may be controlled by a timer comprised in the display driver, for example. Length of the animation depends on the number of bits stored for a sub-pixel 240 in the word 260 and the frame speed of the animation. If a frame speed of four frames per second (FPS) is used, totally 2 second animation effect could be generated. Because the engine of the apparatus is not needed in the power-saving mode, the animation effect may be created with minimal extra power consumption compared to still image presentation.

Fig. 2c shows a schematic drawing of a second display mode in an apparatus in accordance with another example embod iment of the invention . When the apparatus is not actively operated by a user, or the apparatus is locked by the user, a power-saving mode may be provided. In such a mode, an engine comprising the main processor of the apparatus may be switched to a power- saving mode. At the same time, the display module may be switched to a power- saving mode. Before switching to the power-saving mode, power-saving mode image information may be transferred from the engine to the display driver of the display module.

In an example embodiment of the invention, n bits long word 265 for each sub- pixel may be stored to the display driver memory of the display module. First m bits (1 -m) of the word 265 may correspond to a pixel 225 and a sub-pixel 245 of a first image IMG1 . Following m bits of the word 265 may correspond to a pixel and a sub-pixel of a second image, and so on. Last m bits of the word 265 may correspond to a pixel 226 and a sub-pixel 246 of an n/m image IMG(n/m). Altogether n/m images IMG1 - IMG(n/m) may be stored to the memory of the display driver when each sub-pixel of the image IMG1 - IMG(n/m) may have the n- bit word 265 representing the n/m images using m bits for each sub-pixel per image. M may be any number of bits between 1 and n. N need not to be a multiple of m but also unused bits in the word 265 may exist.

In the power-saving mode, an animation may be provided on the display panel by running the n/m images sequentially on the display panel . Displaying of the images may be controlled by a timer comprised in the display driver, for example. Length of the animation depends on the number of bits stored for a sub-pixel 245 in the word 265, number of bits per sub-pixel per image, and the frame speed of the animation. Because the engine of the apparatus is not needed in the power- saving mode, the animation effect may be created with minimal extra power consumption compared to still image presentation.

Fig. 3 shows an example block diagram of an image processing pipeline 300 in which various embodiments of the invention may be applied. An apparatus engine 310 may comprise at least a main processor 320 and a memory 330. A display module 340 may comprise at least a timing controller 350, a display panel 360 and a driver memory 370. On the display panel 360, at least three different image types may be presented.

A normal mode image 380 may be presented using the engine 310 to transfer either directly to the display panel 360, or via the driver memory 370 an image of an n-bit word for each pixel or sub-pixel. N may be 8 bits, for example. A still power-saving image 390 may be presented using the display module 340 only. The engine 310 may be used initially to transfer an image of the n-bit word for each pixel or sub-pixel to the driver memory 370 of the display module 340. In power-saving mode, the still power-saving image 390 may be displayed from the driver memory 370 without processing of the engine 310. The still power-saving image 390 may utilize the whole n-bit word for each pixel or sub-pixel information from the drive memory 370 or only the most significant bit (MSB) for each pixel or sub-pixel. In the latter embodiment, one bit per each red, green and blue sub-pixel may enable 8 colors to be available for the still power-saving image 390.

An animated power-saving image 395 may be presented using the display module 340 only. The engine 31 0 may be used initially to transfer at least two images each with an m-bit word for each pixel or sub-pixel to the n-bit word in the driver memory 370 of the display module 340. In power-saving mode, the animated power-saving image 395 may be displayed from the driver memory 370 without processing of the engine 310, only with the aid of the timing controller 350. The timing controller 350 may control the driver memory 370 to sequentially supply a first m-bit per sub-pixel image and a second m-bit per sub-pixel image to the display panel 360 in a frame speed to provide an animation effect. In case m = 1 bit and n = 8 bits, altogether 8 images may be stored to a driver memory 370. The 8 images each may have one bit per each sub-pixel of red (R), green (G) and blue (B) enabling 8 full resolution images in eight colors. In an example embodiment of the invention, four image frames per second (FPS) may be used as the frame speed by the timing controller 350. That would enable 2 seconds long animation effect. In an example embodiment of the invention, eight different image frames of a rotating ball animation may be created by graphics of eight individual frame images. The frame images may then be combined to a single image word so that each image corresponds to a different significant bit of the word, as shown in Fig. 2b. The image word may be stored in the driver memory 370 of the display module 340, wherefrom the significant bits of the word are sequentially driven to the display panel 360 controlled the timing controller 350. The display panel 360 may change bit from most significant bit (MSB) to least significant bit (LSB) to be shown on the display panel 360 at each frame. Shown bit is changed for example by suitable timing controller 4 times a second. Such a live animation of a rotating ball rotates one round per 2 seconds. This "living" rotating ball animation may not consume much more power than a still image that is updated once per minute. In an example embod iment of the invention, improved animation would be possible by using memory compression. Compression ratio with simple low power methods would be good because power-saving images may be simple due to other technical reasons, l i ke l im ited number of on-state pixel ratio. Another embodiment may include for example scaling of the power-saving animation to 2x2 pixel blocks. Such block size is enough for simple animation and usable especially in PenTile ® pixel structure.

In an example embodiment of the invention, the display module 340 may not comprise internal memory for normal full user interface image. Instead, streaming interface constantly updating image information from the engine memory 330 may be used. Power-saving mode requires, however, memory to display images on screen after powering off the eng ine 31 0. In a simple display module implementation, the module may comprise only a reduced sub-pixel memory, for example one bit per sub-pixel memory, or one bit per pixel memory. In such case, multiple m-bit per sub-pixel image switching may not work because there is not enough memory. However, compression of the images may still enable low power animation because typical power-saving mode image comprises most of the pixels (even more than 95%) as black. Especially organic light emitting diode (OLED) displays have such characteristics. For example, images compressed as portable network graphics (png) or graphics interchange format (gif) format are reduced in size because of the amount of black pixels. More than 1 /8 compression may be achieved. Thus, even one bit per sub-pixel memory may be enough to implement multiple m-bit per sub-pixel images for power-saving mode. The timing controller 350 may be used to control the de-compression of the compressed image information, for example. The timing controller 350 may also be used to control the compression of the image information and storing to the reduced sub-pixel memory. Fig. 4 shows an example block diagram of an apparatus 400 in which various embodiments of the invention may be applied. This may be a user device or apparatus, such as an electronic device, a digital camera device, a personal digital assistant (PDA), a laptop computer, a mobile terminal or other communication device.

The general structure of the apparatus 400 comprises a communication interface module 450, a processor 410 coupled to the communication interface module 450, and a memory 420 coupled to the processor 410. The apparatus further comprises apparatus software 430 stored in the apparatus memory 520 and operable to be loaded into and executed in the processor 410. The software 430 may comprise one or more software modules and can be in the form of a computer program product. The apparatus 400 further comprises a user interface controller 460 coupled to the processor 410 and a display module 440 comprising a timing controller 441 , a driver 442 and a display panel 443. The timing controller 441 may further comprise timing controller software 444 stored in the timing controller memory 445. The driver 442 may further comprise a driver memory 446.

The communication interface module 450 implements at least part of rad io transmission for various embodiments of the invention . The communication interface module 450 may be, e.g ., a radio interface module, such as a WLAN, Bluetooth, GSM/GPRS, CDMA, WCDMA, or LTE (Long Term Evolution) radio module. The communication interface module 450 may be integrated into the apparatus 400 or into an adapter, card or the like that may be inserted into a suitable slot or port of the apparatus 400. The communication interface module 450 may support one radio interface technology or a plurality of technologies. Fig. 4 shows one communication interface module 450, but the apparatus 400 may comprise a plurality of communication interface modules 450.

The apparatus processor 410 may be, e.g., a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), an image signal processor (ISP), a graphics processing unit, or the like. Fig. 4 shows one apparatus processor 410, but the apparatus 400 may comprise a plurality of processors.

The apparatus memory 420 may be for example a non-volatile or a volatile memory, such as a read-only memory (ROM), a programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), a random-access memory (RAM), a flash memory, a data disk, an optical storage, a magnetic storage, a smart card, or the like. The apparatus 400 may comprise a plurality of memories. The memory 420 may be constructed as a part of the apparatus 400 or it may be inserted into a slot, port, or the like of the apparatus 400 by a user. The memory 420 may serve the sole purpose of storing data, or it may be constructed as a part of an apparatus serving other purposes, such as processing data.

The display module 440 may comprise the display panel 443 that may be a liquid crystal display (LCD) or light emitting diode (LED) display, for example. In an example embodiment of the invention, the display panel 443 may be an organic light emitting diode (OLED) display. The timing controller 441 of the display module 440 may comprise a timing controller memory 445 that may be for example a non-volatile or a volatile memory, such as a read-only memory (ROM), a programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), a random-access memory (RAM), a flash memory, or the like. The program code 444 may comprise instructions for controlling the power-saving image displaying on the display panel 443 using the image data stored in the driver memory 446. The driver memory 446 may be for example a non-volatile or a volatile memory, such as a read-only memory (ROM), a programmable read-only memory (PROM), erasable programmable read-only memory (EP ROM ), a random-access memory (RAM), a flash memory, or the like.

The user interface controller 460 may comprise circuitry for receiving input from a user of the apparatus 400, e.g ., via a keyboard, touch screen, graphical user interface shown on the display of the apparatus 400, speech recognition circuitry, or an accessory device, such as a headset, and for providing output to the user via, e.g., a graphical user interface or a loudspeaker. The user interface controller 460 may also be used instead of the timing controller 441 to control the power- saving image displaying. In such a case, the program code 444 may be stored in the user interface controller 460.

In an example embodiment of the invention, the timing controller may be an integrated timing and touch display controller 441 of a touch display apparatus. Such controller 441 may give feedback on the touch display panel 443 of a user's intention to wake up the locked touch display panel 443 using a specified unlock- gesture, for example. A set of specified gesture images may be stored in the driver memory 446. When the apparatus 400 enters to the power-saving mode, the controller 441 may select one of the specified gesture images to be displayed on the panel 443 in power-saving mode. If the user enters the displayed gesture on the touch display panel 443, and the controller 441 recognizes the gesture to be the specified unlock-gesture, the apparatus 400 may exit the power-saving mode. Similar feature may also be used for touch display locking mode, for example. In an example embodiment of the invention, the controller 441 may not display the specified gesture on the display panel 443 in power-saving mode until the user touches the panel 443. After the user touching the display panel 443, the controller 441 may give feedback on the display panel 443 by showing information relating to the gesture. In response to a successful touch gesture by the user, power-saving mode may be ended and the engine of the apparatus may be powered on. Similarly, the display locking mode may be ended.

A skilled person appreciates that in addition to the elements shown in Fig. 4, the apparatus 400 may comprise other elements, such as microphones, cameras, as well as additional circuitry such as input/output (I/O) circuitry, memory chips, application-specific integrated circuits (ASIC), processing circuitry for specific purposes such as source coding/decoding circuitry, channel coding/decoding circuitry, ciphering/deciphering circuitry, and the like. Additionally, the apparatus 400 may comprise a disposable or rechargeable battery (not shown) for powering the apparatus 400 when external power if external power supply is not available. Stretchability for the battery may be achieved by packing electrolyte fluids in a stretchable housing. Fig. 5 shows a flow diagram showing operations in an apparatus in accordance with an example embodiment of the invention. In step 500, the operation is started. In step 510, at least two images each with an m-bit word for each pixel are provided to an n-bit word for each pixel in the image memory of a driver in a display module. In step 520, the at least two images each with the m-bit word for each pixel are stored to the image memory as the n-bit word for each pixel, wherein n is greater than or equal to 2m. In step 530, the driver is controlled to sequentially supply the images each with the m-bit word for each pixel to a display panel of the display module for providing an animation effect. In step 540, the operation is ended.

Various embodiments have been presented. It should be appreciated that in this document, words comprise, include and contain are each used as open-ended expressions with no intended exclusivity.

The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments of the invention a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented above, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.

Furthermore, some of the features of the above-disclosed embodiments of this invention may be used to advantage without the corresponding use of other features. As such , the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.

Claims

Claims:

1 . A display module comprising:

a display panel having a plurality of pixels;

control the driver to sequentially supply the images with the m-bit word for each pixel to the display panel, to provide an animation effect.

2. The display module of claim 1 , wherein the display panel comprises an organic light emitting diode panel, and m most significant bits of the n-bit word relate to the first image with the m-bit word for each pixel and following m bits of the n- bit word relate to the second image with the m-bit word for each pixel.

3. The display module of claim 1 or 2, wherein the driver comprises a scan driver configured to supply a scan signal to the display panel, and a data driver configured to supply a data signal to the display panel.

4. The display module of claim 3, wherein the timing controller is configured to generate a data control signal to control the data signal and a scan control signal to control the scan driver.

5. The display module of any preceding claim, wherein the image memory comprises an 8-bit word for each pixel.

6. The display module of any preceding claim, wherein the image memory comprises eight 1 -bit words for each pixel.

7. The display module of claim 6, wherein eight images with the 1 -bit word for each pixel are stored as an 8-bit word for said pixel.

8. The display module of any preceding claim, wherein the pixel comprises at least one of the following sub-pixels: red, green and blue.

9. The display module of any preceding claim, wherein the driver is sequentially controlled to supply the images each with the m-bit word for each pixel with a speed greater than two image frames per second.

10. The display module of any preceding claim, wherein the display module is further caused to compress the m-bit word for each pixel in the n-bit word in the image memory.

1 1 . The display module of any preceding claim, wherein the display module is further caused to scale the supplied images each with the m-bit word for each pixel as 2x2 pixel blocks.

12. The display module of any preceding claim, wherein the display module is further caused to define an upper limit for simultaneously active pixels.

13. An apparatus comprising:

a display module of any preceding claim;

transfer, over a communication interface, the at least two images each with the m-bit word for each pixel from the apparatus memory to the image memory of the driver for storing.

14. A method comprising:

providing at least two images each with an m-bit word for each pixel to an n-bit word for each pixel in the image memory of a driver in a display module; storing the at least two images each with the m-bit word for each pixel to the image memory as the n-bit word for each pixel, wherein n is greater than or equal to 2m; and

controlling the driver to sequentially supply the images each with the m-bit word for each pixel to a display panel of the display module for providing an animation effect.

15. A computer program comprising computer executable program code configured to cause an apparatus, when executing the program code, to perform the method of claim 14.