Display module with storage of an image in an internal memory

Abstract

The invention relates to a method for displaying data, the method being implemented in a display module comprising a screen and a control module suitable for controlling light elements of the screen according to data over a data interface. The display module comprises a memory storing at least one image. The method comprises the steps of: - upon detecting (202; 203) a lack of availability of data over the data interface and receiving a power supply signal over at least one power supply interface, accessing (204), by means of the control module, the at least one image in the memory; - controlling (205), by means of the control module, the light elements to display the at least one image.

Description

[0001] Description

[0002] Title: Display module with storage of an image in an internal memory

[0003] The present invention relates to the field of displaying visual data, in particular image data. The invention applies in particular, but not exclusively, to images displayed for lighting functions, such as an aesthetic function or a signaling function in a motor vehicle.

[0004] It is known to use display modules comprising a screen inside or outside a motor vehicle, in order to perform a signaling function or for aesthetic reasons. This may, for example, be a welcome display when the vehicle is started, but also a signaling or aesthetic display while the vehicle is switched on.

[0005] Such a display module typically receives still images or a series of images from a video, via a data channel from a vehicle control module, for example from a graphics processing unit, or GPU, such as a graphics card.

[0006] If data is unavailable on the data channel, for example due to a fault or a graphics card startup time, the display module generally does not display any image, which causes an interruption of service, or a delay, in the aesthetic or signaling function.

[0007] There is therefore a need to enable better continuity or responsiveness in the performance of lighting functions performed by a display module, particularly for motor vehicles.

[0008] To this end, a first aspect of the invention relates to a method for displaying data, the method being implemented in a display module comprising a screen and a control module capable of controlling luminous elements of said screen as a function of data received by the display module on a data interface, the display module comprising a memory storing at least one image, the method comprising the following steps: - upon detection of unavailability of data on the data interface and reception of a power supply signal on at least one power supply interface, access by the control module to said at least one image in the memory:

[0009] - control of said light elements by the control module to display said at least one image.

[0010] Local storage of at least one image in the display module ensures continuity of lighting, aesthetic or signaling functions when data is unavailable on the input interface. In the event of a delay in receiving data on the data interface, it allows for better responsiveness in displaying a lighting function.

[0011] According to embodiments, the unavailability of data on the data interface may be a failure to receive data on the data interface or a reception of data with errors.

[0012] Thus, the method according to the invention makes it possible to ensure better continuity or reactivity in the display, for several causes of unavailability of data on the data interface, including when the data received is corrupted or contains errors.

[0013] According to embodiments, when the detection of the unavailability of data on the data interface is subsequent to initial operating conditions in which data is received on the data interface and a power signal is received on said at least one power interface, the detection of the unavailability may comprise the detection of an interruption of reception of data on the data interface and the control module may access at least one first image in the memory and may control said light elements to display said at least one first image.

[0014] Thus, it is permitted to display a first default image in case of data unavailability. The first image may indicate that the display device is in fail-safe mode, or FSO, or may freeze the lighting function that was performed under the initial operating conditions.Additionally or alternatively, when the detection of unavailability is subsequent to initial operating conditions in which no data is received on the data interface and no power signal is received on said at least one power interface, the detection of unavailability may be a detection of an absence of data on the data interface while a power signal is received on said at least one power interface, the control module may access at least one second image in the memory, the at least one second image preferably being different from the first image, and may control said light elements to display said at least one second image.

[0015] This improves the responsiveness of the display module's lighting function. The lighting module typically receives data from a GPU, which has a startup time that results in a delay in receiving data over the data interface.

[0016] Additionally, said at least one second image may be a series of second images forming an animation.

[0017] This makes it possible to create a welcome animation when starting the display module, which is advantageous, particularly when the display module is integrated into equipment such as motor vehicle equipment.

[0018] Additionally or alternatively, the method may further comprise, following the display of said at least one second image, the reception of calibration data from the screen, and the storage in the memory of the calibration data by the control module.

[0019] Such an embodiment is advantageous, particularly when the display module is first started up. The calibration data then makes it possible to improve the display of the image stored in the memory.

[0020] When the second image is different from the first image, it is understood that it is possible to display a second image for a home scenario when all the components of the motor vehicle are not yet initialized, and a first image indicating that the display device is in default safety mode, or FSO. In this way, it is possible for the user to realize by simple visual inspection of a malfunction in the communication between the vehicle and the device when the device displays the first image, while benefiting from a home scenario using the second image.

[0021] Additionally, the method may further comprise, following the display of said at least one second image, waiting for a predetermined time for data reception on the data interface, following which, once the predetermined time has elapsed and if no data has been received, the first image is displayed instead of the second image.

[0022] Such an embodiment makes it possible to display the first image, for example to inform of the malfunction of the communication between the vehicle and the device when the second image was displayed when the display module was started, or to display a default image corresponding to the performance of the display function, which is advantageous when the second image corresponds to a reception scenario and might not meet the regulatory constraints of the signaling devices of motor vehicles; for example, the image of the reception scenario may have colorimetry or photometry incompatible with these regulatory constraints. In another example, and in the specific case where the at least one second image is a succession of images forming an animation, the standards in force in most countries at the date of filing of the application do not allow an animation to be displayed while the vehicle is moving.

[0023] According to embodiments, the method may further comprise receiving an update of the at least one image on the data interface, and writing by the control module to the memory to replace the at least one image with the update.

[0024] This makes it possible to update the image stored in the memory, which improves the customization of the lighting functions performed by the display module and to vary the default image or the lighting animation displayed in the event of data unavailability and power reception.

[0025] According to embodiments, the method may further comprise storing said at least one image in the memory of the display module, before a first commissioning of said display module.

[0026] Therefore, there is no need to configure the display module when it is first put into operation.

[0027] A second aspect of the invention relates to a computer program comprising instructions for implementing the method according to the first aspect of the invention, when these instructions are executed by a processor.

[0028] A third aspect of the invention relates to a display module comprising:

[0029] - a memory storing at least one image;

[0030] - at least one power supply interface capable of receiving a power supply signal;

[0031] - a data interface capable of receiving data;

[0032] - a screen comprising a plurality of light elements;

[0033] - a control module capable of controlling the light elements of the screen according to the data received on the data interface, of detecting unavailability of the data on the input interface, and capable of, upon detection of unavailability upon receipt of a power signal, accessing said at least one image in the memory and controlling the light elements to display said at least one image.

[0034] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings in which:

[0035] [Fig 1] illustrates a display system according to embodiments of the invention;

[0036] [Fig 2] is a diagram illustrating the steps of a method of displaying an image according to embodiments of the invention.

[0037] The description focuses on the features that distinguish the method and the display module from those known in the state of the art. Figure 1 illustrates a display system 1 for a motor vehicle according to embodiments of the invention.

[0038] The display system 1 comprises a display module 100 capable of performing at least one lighting function among an aesthetic function and / or a signaling function. The signaling function comprises the display of data for informational purposes for a user. The display module 100 can be integrated into exterior equipment of a motor vehicle, in particular for a signaling function, or into interior equipment of a motor vehicle, in particular for a signaling function to the driver, for an aesthetic function such as the display of a welcome message when starting the vehicle. No restriction is attached to the equipment which integrates the display module 100, which can be a bodywork element, a headlight, a door, a dashboard element or any other interior or exterior equipment of a motor vehicle.

[0039] The display module 100 comprises a control module 101 capable of controlling a screen 102, in particular as a function of image or video data received via a first interface 105, called data interface 105 in the following.

[0040] There are no restrictions on the technology of the screen 102, which may comprise a matrix of individually controllable light elements.

[0041] According to embodiments, each of the light elements may be a light-emitting semiconductor chip whose dimensions are between 150 pm and 300 pm. Such a chip is called a mini-LED. Alternatively, and preferably, each of the light elements comprises at least one light-emitting semiconductor chip whose dimensions are less than 150 pm, for example between 5 pm and 80 pm. Such a chip is called a micro-LED. Such chips may be mounted, directly or indirectly, on a substrate, such as a ceramic substrate.A ceramic substrate is understood to mean a substrate made of a material of crystalline, or partially crystalline or amorphous structure, such as glass or alumina, consisting of essentially inorganic substances, and which is formed by a molten mass which solidifies on cooling, or which is formed and matured, at the same time or subsequently, by the action of heat and / or pressure.

[0042] Advantageously, the ceramic substrate is an alumina (AI2O3) or aluminum nitride (AIN) substrate. It should be noted that the glass substrate (based on borosilicate) is more commonly used due to its dielectric properties and its production cost. The substrate may have a thickness of between 400 and 600 pm, for example equal to 500 pm. Alternatively, the substrate may be of the high-density printed circuit type, HDI PCB, with a thickness of between 400 and 600 pm, for example equal to 500 pm, in the case of active matrix control of the light sources, or between 900 and 1100 pm, for example equal to 1 mm, in the case of passive matrix control of the light elements.

[0043] Alternatively, the light elements can be organic LED or OLED, for example with active matrix control, also called AMOLED. Alternatively, the light elements can be LCD cells, for "Liquid Crystal Display" in English.

[0044] As indicated, the control module 101 can control the luminous elements of the screen in active matrix or, preferably, in passive matrix.

[0045] In an active matrix, the control module 101 controls control elements respectively associated with each of the light elements or with a group of light elements. Each light element is thus associated with an active control element. Advantageously, each light element is mounted and connected to the control element with which it is associated. For example, each control element comprises a thin-film transistor, also called TFT, for "Thin Film Transistor" in English, on which the associated light element, or the associated group of light elements, is mounted and connected. The assembly of the plurality of light elements of the screen 102 and the plurality of active control elements forms an active matrix.Alternatively, the emission face of the substrate may comprise one or more thin connection sub-layers, in particular with a thickness of less than 50 μm, incorporating a plurality of active control elements, each active control element being arranged to control at least one of the light elements with which it is associated, and each light element being mounted and connected directly to the emission face of the substrate, substantially in line with a control element of the thin connection sub-layer(s), to which it is connected. Each control element may be of the integrated microcircuit type comprising at least one transistor and a memory.

[0046] In a passive matrix, the control module 101 is capable of sequentially connecting and disconnecting each of the light elements to a power supply, received via a first power supply interface 107.1 described later, and to ground. In this case, the light elements can be mounted directly on the emission face of the substrate, forming a passive matrix, and control units 103 can be arranged to control the passive matrix according to control instructions received by the control module 101. In order to produce such a passive matrix, the display module 100 can comprise a plurality of devices for controlling the electrical power supplied to the light elements, the control devices being able to be mounted on the face opposite the emission face of the substrate.Each driver device may be mounted on the opposite face proximate a through hole to drive the electrical power supplied to a light element on the other side of the through hole, on the light emitting face of the substrate.

[0047] A set of control devices can be controlled by a control unit 103, each control unit being able to be an integrated circuit. For example, such integrated circuits 103 can in particular control several hundred light elements, via their respective control devices. The light elements of the screen 102 are thus distributed into subsets of light elements, each subset of light elements being controlled by the control module 101 via a dedicated control unit 103.

[0048] For example, each control unit 103 can allow the control of a 16*48 matrix, or 768 light elements. The display module 100 can thus comprise several dozen control units 103, for example between 20 and 40 control units 103, in particular 30 control units 103. Preferably, the control module 101, the control units 103 and the light elements of the screen 102 are arranged on the same substrate, which reduces the size since the number of cables is then restricted to the cables coming from the interfaces 105, 106, 107.1 and 107.2 described below.

[0049] The control module 101 is thus responsible for distributing control signals between the control units 103, so as to allow a coherent display of an image obtained from the different subsets of light elements. The control module 101 thus forms a real-time controller, also called a “time controller” in English. Such a type of control is well known and is not described further in the present description.

[0050] Note that in the embodiment where the light elements are controlled in an active matrix, the display module 100 does not include the control units 103, the control module 101 directly controlling the control elements associated with the light elements.

[0051] The display module 100 is distinguished from a lighting module capable of projecting light. In the display module 100, the light elements of the screen 102 are placed directly opposite a protective glass so as to be directly visible from outside the display module 100. On the contrary, in a lighting module, the light elements emit light which is projected outside the lighting module by an optical projection system which may comprise one or more lenses and / or mirrors, and the light elements are not directly visible from outside the lighting module.

[0052] The display module 100 of FIG. 1 further comprises:

[0053] - a data interface 105 capable of receiving data, such as still images or a video stream, from a graphics control module 120, or GPU, such as a graphics card for example. The control module is thus capable of sending image or video data, from which the control module 101 determines control signals intended for the control elements 103, in the passive matrix embodiment. The data interface 105 is generally unidirectional, and is capable of receiving image data from the GPU 120, without being able to transmit data in return;

[0054] - a diagnostic interface 106, allowing the control module 101 to exchange, bidirectionally, diagnostic data with the GPU 120 or with another control module of the vehicle, such as a centralized control module of the ECU type for example, for “Electronic Control Unit” in English.

[0055] The light elements of the screen 102 are powered by a power supply 110 of the vehicle via a first power supply interface 107.1. The control module 101 is powered by a power supply 110 of the vehicle via a second control power supply interface 107.2.

[0056] The power supply 110 can further power the GPU 120, via a power cable not shown in FIG. 1.

[0057] The control module 101 may preferably comprise a processor such as a microcontroller element. The control module 101 may in particular comprise a chip of the “Field Programmable Fate Array”, FPGA, “Application Specific Integrated Circuit”, ASIC, or “Complex Programmable Logic Device”, CPLD type. These elements are configured by means of an appropriate computer program to implement the steps described with reference to FIG. 2.

[0058] The display module 100 may further comprise a memory 104 such as a “Random Access Memory” type memory, RAM, or a “Read Only Memory” type memory, ROM, or any other type of memory (Flash, EEPROM, etc.). Alternatively, the memory 402 comprises several memories of the aforementioned types. Preferably, the memory 402 is a non-volatile memory. Preferably, the memory 104 is a Flash memory.

[0059] An interruption of a lighting, signaling or aesthetic function, or a delay in the implementation of such a lighting function, may occur in the solutions according to the prior art. This is particularly the case when starting the vehicle. Indeed, during such a start, the power supply 110 supplies the display module 100 as well as the GPU 120. However, starting the GPU 120 imposes a delay on the reception of data via the data interface 105 by the display module 100. During this delay, the control module 101 does not receive any image data and therefore cannot control the screen 102 to display an image or an animation. This results in a delay in the display of an image or an animation, which is particularly penalizing in the case of a welcome function or "welcome scenario".In another context, in the event of a fault on the data interface 105, for example in the event of an interruption of the received data, or in the event of the reception of corrupted or error-containing data, the lighting function performed by the display module 100 is interrupted. The display module 100 can then switch to a fail-safe mode, or integrated safety mode, also called FSO, for “Fail Safe Operation” in English.

[0060] In order to avoid such interruptions or delays in lighting functions, the present invention proposes storing a still image or video / animation in the memory 104, the image or video being displayed in the event of unavailability of data on the data interface 105, as will be better understood from the description of FIG. 2. The unavailability may be an absence of data flow, due to a delay in startup or a failure of the GPU 120, or may be the reception of corrupted or error-ridden data.

[0061] The control module 101 is thus able to access in read mode the data stored in the memory 104, in particular the stored image or video. Furthermore, optionally, the control module 101 may be able to access in write mode the memory 104, in particular for updating the stored image or video, or for storing calibration data relating to the screen 102. In particular, when the vehicle is first started, calibration data may be received by the control module 101 via the data interface 105 or the diagnostic interface 106. This calibration data may describe the operation of the light elements of the screen 102, or may allow compensation for differences in power or colors between the light elements. No restriction is attached to such calibration data.Further, the control module 101 may receive an image update or an update of a series of images forming an animation via the data interface 105, and may store such an update, replacing the previous image or series of images, in the memory 104.

[0062] Figure 2 shows a diagram illustrating the steps of a data display method implemented by a display module 100 according to embodiments of the invention.

[0063] In a step 200, at least one image is stored in the memory 104. Such an image may be a still image, by default, or may be a series of images forming an animation, such as a welcome animation. For example, the memory 104 may store a first image which is a default image to be displayed in the event of an interruption in the reception of data on the data interface 105, as described later. In addition or as an alternative, the memory 104 may store at least one second image, preferably a series of second images forming a welcome animation, to be displayed when the vehicle is started, during the period during which no data is available on the data interface 105, due to the start-up of the GPU 120. Preferably, the duration of the animation is equal, or equal to within 10%, of the start-up duration of the GPU 120.

[0064] In a step 201, the display module 100 is in initial operating conditions. The adjective “initial” designates conditions which are prior to the steps 202 and 203 described below. In first initial conditions, the display module 100 is powered by the power supply 110 and receives data on the data interface 105 from the GPU, and the control module 101 controls the luminous elements of the screen 102 according to the received data. The first initial conditions can thus be nominal operating conditions. In second, alternative initial conditions, the display module 100 is not powered by the power supply 110 and receives no data from the GPU 120. Such initial conditions can in particular correspond to a situation in which a motor vehicle comprising the system 1 is switched off.

[0065] In a step 202, the control module 101 detects an unavailability of data on the data interface 106, and in a step 203, the control module 101 detects that the display module 100 is powered by the power supply 110. The detections of the unavailability of the data and of the power supply are thus cumulative conditions which must be fulfilled simultaneously for the implementation of the step 204 described later. An unavailability of data can correspond to:

[0066] - the absence of data on the input interface, either due to a delay in turning on the GPU 120, or due to an interruption in the reception of data; or

[0067] - upon receipt of corrupted or error-ridden data on the data interface 105.

[0068] Following steps 202 and 203, the control module 101 accesses in reading mode at least one of the images stored in the memory 104., in a step 204

[0069] The unavailability may thus be an interruption in the reception of data or the detection of errors in the received data, following the first initial conditions. Indeed, the data channel is a fragile channel and such interruptions may occur. In the event of detection of such an interruption in the reception of data or in the event of detection of errors, despite continuity in the power supply received by the display module 100, the control module 101 can access in reading the first default image at a step 204, and can control the screen 102 so as to display the default image at a step 205. The aforementioned unavailability may follow the activation of a fail-safe mode FSO.The activation of the FSO mode may be initiated by the control module 101 upon detection of a fault on the data interface 105, such as an absence of data, or upon detection of a fault, or errors, in the received data itself, or upon receipt of a fault message on the diagnostic interface 106, for example from the GPU 120 itself. When the control module 101 detects a fault on the data interface 105 or in the received data, the activation of the FSO mode may be signaled to the GPU via the diagnostic interface 106.

[0070] Alternatively, the unavailability of data on the data interface 105 may be a delay in receiving the data, in particular following the start-up of a vehicle comprising the system 1. In this case, the power supply is received by the display module 100 as soon as the vehicle is started, but the GPU 120 generally takes several seconds to be started, which creates a fault in receiving data on the data interface 105. Such a fault is thus consecutive to the second initial conditions, in which the power supply 110 and the GPU 120 are initially stopped. Upon detection of an absence of data reception, following the second initial conditions and while the power supply is received on the interface 107.1, the control module 101 can read access to said at least one second image different from the first image in the memory 104, at step 204, and can control the light elements of the screen 102, so as to display said at least one second image. As previously explained, said at least one second image can be an animation such as a welcome animation, which makes it possible to display such an animation while the GPU is started.

[0071] The control module 101 is thus able to differentiate between detections in steps 202 and 203 which are consecutive to the first initial conditions and detections in steps 202 and 203 which are consecutive to the second initial conditions, when the memory stores the first image, and said at least one second image. Alternatively, the control module 101 is only able to implement steps 202 and 203 following the first initial conditions, or only following the second initial conditions, when the memory 104 only stores the first image or said at least one second image.

[0072] In an optional step 206, the control module 101 may receive an update of at least one image stored in the memory 104, via the data interface 105. Such an update may in particular be received during the first initial conditions described above, when data is received on the data interface 105 and the display module 100 is powered. The image update may be received from the GPU 120 or from another module, such as a cellular data reception module of a motor vehicle for example. A signal may be received on the diagnostic interface 106 indicating that the data received on the data interface 105 is image update data. Such a signal may indicate whether the update concerns the first image or said at least one second image, when the memory 104 stores several images.Upon receipt of such an update, the control module 101 may write to the memory 104 in order to replace the image with the updated image.

[0073] According to another optional step 207, the control module 101 can receive calibration data. Such calibration data can in particular be received following the first start-up of the display module 100, and following the display of a third image, called the calibration image, or following the display of the at least one second image as a variant. Thus, the memory 104 can further store a third image to be displayed during the first start-up of the vehicle, that is to say during the first implementation of steps 202 and 203 following the second initial conditions. In this case, an external device can evaluate calibration data as a function of the display of the third image, or of the at least one second image, on the screen 102, and communicate this data to the display module 100.Indeed, the light elements may have variations in power and / or color, and the storage of calibration data in the memory 104 in step 207 allows the control module 101 to take the calibration data into account when controlling the light elements of the screen 102. Alternatively, the calibration data are used by the control module 101 to modify the images stored in the memory 104, and it is then not necessary to take the calibration data into account when controlling the screen 102.

[0074] The present invention is not limited to the embodiments described above as examples; it extends to other variants.

Claims

Claims 1. Method for displaying data, the method being implemented in a display module (100) comprising a screen (102) and a control module (101) capable of controlling luminous elements of said screen as a function of data received by the display module on a data interface (105), the display module comprising a memory (104) storing at least one image, the method comprising the following steps: - upon detection (202; 203) of unavailability of data on the data interface and receipt of a power signal on at least one power interface (107.1; 107.2), access (204) by the control module to said at least one image in the memory; - control (205) of said light elements by the control module to display said at least one image.

2. The method of claim 1, wherein the unavailability of data on the data interface (105) is a lack of reception of data on the data interface or a reception of data comprising errors.

3. Method according to claim 1 or 2, wherein when the detection (202) of the unavailability of data on the data interface (105) is subsequent to initial operating conditions (201) in which data is received on the data interface and a power signal is received on said at least one power interface, the detection of the unavailability comprises the detection of an interruption of reception of data on the data interface and the control module accesses (204) at least a first image in the memory and controls (205) said light elements to display said at least one first image.

4. Method according to one of the preceding claims, wherein when the detection (202) of the unavailability is consecutive to initial operating conditions in which no data is received on the data interface and no power signal is received on said at least one power interface (107.1; 107.2), the detection of the unavailability is a detection of an absence of data on the data interface (105) while a power signal is received on said at least one power interface (107.1; 107.2), the control module accesses at least one second image in the memory and controls said light elements to display said at least one second image.

5. Method according to the combination of claims 3 and 4, wherein said at least one second image is different from the first image.

6. Method according to claim 4 or 5, wherein said at least one second image is a series of second images forming an animation.

7. Method according to claim 4, 5 or 6, further comprising, following the display of said at least one second image, the reception (207) of calibration data from the screen, and the storage in the memory (104) of the calibration data by the control module (101).

8. Method according to one of the preceding claims, further comprising receiving (206) an update of said at least one image on the data interface, and writing by the control module (101) in the memory (104) to replace said at least one image with the update.

9. Method according to one of the preceding claims, further comprising storing (200) said at least one image in the memory (104) of the display module (100), before a first commissioning of said display module.

10. Computer program comprising instructions for implementing the method according to any one of claims 1 to 8, when these instructions are executed by a processor (101).

11. Display module (100) comprising: - a memory (104) storing at least one image; - at least one power supply interface (107.1; 107.2) capable of receiving a power supply signal; - a data interface (105) capable of receiving data; - a screen (102) comprising a plurality of light elements; - a control module (101) capable of controlling the light elements of the screen according to the data received on the data interface, of detecting unavailability of the data on the input interface, and capable of, upon detection of unavailability upon receipt of a power signal, accessing said at least one image in the memory and controlling the light elements to display said at least one image.

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