CN116092422A

CN116092422A - Display driving method and storage medium

Info

Publication number: CN116092422A
Application number: CN202310070526.6A
Authority: CN
Inventors: 朱修殿; 邵伟; 黄晓峰; 张慧
Original assignee: Caishan Microelectronics Suzhou Co ltd
Current assignee: Caishan Microelectronics Suzhou Co ltd
Priority date: 2023-01-26
Filing date: 2023-01-26
Publication date: 2023-05-09

Abstract

The invention relates to a display driving method and a storage medium, belonging to the field of displays, wherein the method comprises the following steps: receiving gray data to be displayed, wherein the gray data at least comprises one frame of display data of one pixel point; for each pixel point, sequentially scanning display data corresponding to the pixel point, and determining the driving duration and/or driving current of the pixel point in the current frame; and driving each pixel point according to the driving time length and/or the driving current so as to display the gray scale corresponding to the display data. The problem of insufficient opening time of the MOS tube caused by too short driving time can be avoided, and low gray scale can be effectively distinguished.

Description

Display driving method and storage medium

Technical Field

The present invention relates to the field of displays, and in particular, to a display driving method and a storage medium.

Background

In the related art, the conventional driving method of the display is mainly PWM (pulse width modulation ) method, and the brightness of the gray scale of the pixel is mainly determined by the light emitting time. The display time of the pixel points is short in low gray scale, so that the opening time of the MOS tube is insufficient, and the problem that some low gray scales are difficult to distinguish is caused.

Disclosure of Invention

In order to overcome the problems in the related art, the present invention provides a display driving method and a storage medium. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

According to a first aspect of an embodiment of the present invention, there is provided a display driving method including:

receiving gray data to be displayed, wherein the gray data at least comprises one frame of display data of one pixel point;

for each pixel point, sequentially scanning display data corresponding to the pixel point, and determining the driving duration and/or driving current of the pixel point in the current frame;

and driving each pixel point according to the driving time length and/or the driving current so as to display the gray scale corresponding to the display data.

Optionally, the display data includes a plurality of bits, and a driving duration and/or a driving current corresponding to each bit are different.

Optionally, scanning display data corresponding to the pixel in turn, and determining a driving duration and/or a driving current of the pixel in the current frame includes:

and in response to the values of the first N bits scanned to the plurality of bits are all zero, determining the driving current of the pixel point in the current frame according to the values of the last M bits.

and in response to the scanning that the value of any one bit of the first N bits of the plurality of bits is not zero, determining the driving duration of the pixel point in the current frame according to the values of the first N bits and the last M bits.

Optionally, under the condition that the values of the first N bits are all zero, the driving duration corresponding to the last M bits in the first N bits is equal to the driving duration corresponding to the last bit in the first N bits, and the driving current corresponding to each bit is sequentially reduced.

Optionally, the driving duration corresponding to each bit in the first N bits of the display data is sequentially reduced, and the driving currents are the same;

and under the condition that the value of any one bit in the values of the first N bits is not zero, the driving time length corresponding to each bit in the last M bits is sequentially reduced, and the driving currents are the same, wherein the driving time length corresponding to the first bit in the last M bits is smaller than the driving time length corresponding to the last bit in the first N bits.

Alternatively, N is equal to 4 and m is equal to 4;

under the condition that the values of the first N bits are all zero, the driving currents corresponding to the last M bits are sequentially 1/2I,1/4I,1/8I and 1/16I, and the driving time length corresponding to the last M bits is 1T.

Optionally, the driving time lengths corresponding to the first N bits are 8T,4T,2T and 1T in sequence, and the driving current is 1I;

and under the condition that any bit in the values of the first N bits is not zero, the driving time lengths corresponding to the last M bits are sequentially 1/2T,1/4T,1/8T and 1/16T, and the driving current is 1I.

Optionally, the display is a Micro light emitting diode Micro-LED display, or a Micro organic light emitting diode Micro-OLED display, or an active matrix organic light emitting diode AMOLED display.

According to a second aspect of embodiments of the present invention there is provided a computer readable storage medium having stored thereon computer program instructions which when executed by a processor implement the steps of the method of any of the first aspects of the present invention.

The technical scheme provided by the embodiment of the invention can comprise the following beneficial effects: by receiving the display data of each pixel, determining the driving time and/or the driving current of each pixel according to the display data, and driving each pixel according to the driving time and/or the driving current, the pixel of the display can be driven based on the driving time corresponding to the display data, so that the problem of insufficient opening time of the MOS tube caused by too short driving time can be avoided, and low gray scale can be effectively distinguished.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Drawings

The above and other features, advantages and aspects of embodiments of the present invention will become more apparent by reference to the following detailed description when taken in conjunction with the accompanying drawings. The same or similar reference numbers will be used throughout the drawings to refer to the same or like elements. It should be understood that the figures are schematic and that elements and components are not necessarily drawn to scale. In the drawings:

fig. 1 is a flowchart illustrating a display driving method according to an exemplary embodiment.

Fig. 2 is a schematic diagram of a drive unit according to an exemplary embodiment.

Fig. 3 is a block diagram illustrating a display driving apparatus according to an exemplary embodiment.

Fig. 4 is a block diagram illustrating an apparatus for display driving according to an exemplary embodiment.

Detailed Description

Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While the invention is susceptible of embodiment in the drawings, it is to be understood that the invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather are provided to provide a more thorough and complete understanding of the invention. It should be understood that the drawings and embodiments of the invention are for illustration purposes only and are not intended to limit the scope of the present invention.

It should be understood that the various steps recited in the method embodiments of the present invention may be performed in a different order and/or performed in parallel. Furthermore, method embodiments may include additional steps and/or omit performing the illustrated steps. The scope of the invention is not limited in this respect.

The term "including" and variations thereof as used herein are intended to be open-ended, i.e., including, but not limited to. The term "based on" is based at least in part on. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments. Related definitions of other terms will be given in the description below.

It should be noted that the terms "first," "second," and the like herein are merely used for distinguishing between different devices, modules, or units and not for limiting the order or interdependence of the functions performed by such devices, modules, or units.

It should be noted that references to "one", "a plurality" and "a plurality" in this disclosure are intended to be illustrative rather than limiting, and those skilled in the art will appreciate that "one or more" is intended to be construed as "one or more" unless the context clearly indicates otherwise.

The names of messages or information interacted between the devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of such messages or information.

It can be appreciated that before using the technical solutions disclosed in the embodiments of the present invention, the user should be informed and authorized of the type, the usage range, the usage scenario, etc. of the personal information related to the present invention in an appropriate manner according to the relevant laws and regulations.

Meanwhile, it can be understood that the data (including but not limited to the data itself, the acquisition or the use of the data) related to the technical scheme should conform to the requirements of the corresponding laws and regulations and related regulations.

In order to make those skilled in the art more understand the improvement of the technical solution provided by the present invention, the present invention first describes the related art:

in the related art, the driving method of the conventional display is mainly a PWM method, and the brightness of the gray scale of the pixel is mainly determined by the light emitting time. Moreover, the display time of the pixel points is short in low gray scale, so that the opening time of the MOS tube is insufficient, and the problem that some low gray scales are difficult to distinguish is caused.

For example, the 8bit 256 gray scale is used to divide the LED lighting time into 255 parts, the full black is Code0, and the full lighting is Code255. Based on the PWM display method, the following display method according to bit scanning (also called sub-field scanning) is invented, the time length bit T is based on the time corresponding to the first bit, the second bit is 2T, the third bit is 4T, the fourth bit is 8T, the 5 th bit is 16T, the 6 th bit is 32T, the 7 th bit is 64T, and the 8 th bit is 128T, so that 256 gray scales can be formed, one frame needs to be divided into 256 sub-frames, the refresh rate is super-large, and the realization difficulty is greatly increased.

In this regard, in order to reduce sub-frames, the times corresponding to 8bit data D <7:0> are 8T,4T,2T, 1/2T,1/4T,1/8T,1/16T, respectively, thus requiring 19 sub-frames. However, since 1/2T,1/4T,1/8T,1/16T are the times displayed in the 1T reference time of 1/2 1/41/8 1/16T, the method has the defects of insufficient opening time of the MOS tube and difficult distinction of some low gray scales due to short display time.

In order to solve the problems in the related art, the present invention provides a display driving method and a storage medium.

Fig. 1 is a flowchart illustrating a display driving method, an execution subject of which may be, for example, a driving unit of a display or may be, for example, a control module of the driving unit, according to an exemplary embodiment, and the method includes:

s101, receiving gray data to be displayed, wherein the gray data at least comprises one frame of display data of one pixel point.

The gray data may be determined based on a picture image to be displayed, and the gray data is used to control each pixel point in the display to display a gray corresponding to the picture image, and for each pixel point, the display data may be transmitted in a bit stream manner, where each X bits corresponds to the display data of a frame, and the X may be calibrated based on an actual display requirement, for example, may be 8 or 16, that is, the gray of display of each frame may be indicated by 8 bits or 16 bits of display data.

S102, for each pixel point, sequentially scanning display data corresponding to the pixel point, and determining the driving time length and/or the driving current of the pixel point in the current frame.

It can be understood that the longer the driving time length is, the higher the display gray level of the pixel point is, i.e. the brighter the picture, the shorter the driving time length is, and the lower the display gray level of the pixel point is, i.e. the darker the picture is; the larger the driving current is at a certain driving time, the higher the display gray level of the pixel point is, the smaller the driving current is, and the lower the display gray level of the pixel point is.

And S103, driving each pixel point according to the driving time length and/or the driving current so as to display the gray scale corresponding to the display data.

In the embodiment of the invention, the pixel point of the display can be driven based on the driving time corresponding to the display data by receiving the display data of each pixel point, determining the driving time and/or the driving current of each pixel point according to the display data and driving each pixel point according to the driving time and/or the driving current, so that the problem of insufficient opening time of the MOS tube caused by too short driving time can be avoided, and low gray scale can be effectively distinguished.

In some alternative embodiments, the display data includes a plurality of bits, each bit corresponding to a different drive duration and/or drive current.

The display data may include 8 bits, where the driving duration and the driving current corresponding to each bit may all decrease in sequence, or the driving duration corresponding to each bit may be the same or the same, or the driving duration of a part of bits may decrease in sequence, the driving current is the same, the driving current of another part of bits decreases in sequence, and the driving duration is the same.

For example, the driving current corresponding to each bit in 8 bits is sequentially reduced, the driving duration is the same, the driving currents corresponding to the 8 bits are 8i,4i,2i, 1/2i,1/4i,1/8i,1/16i, and the driving duration corresponding to the 8 bits is T, so that the driving current of the pixel in the frame can be determined based on the 8 bits, and further the pixel driving is performed in the duration of 1T based on the driving current, so as to realize gray scale display of 0-255.

It should be noted that the time T and the current I mentioned in the above examples and the following may be a pre-calibrated time length and a pre-calibrated current magnitude, and the specific values thereof are not limited by the present invention.

Alternatively, the driving duration or driving current corresponding to each bit may be determined based on the values of other bits, as in the following alternative embodiments, which are not described herein.

In some optional embodiments, sequentially scanning display data corresponding to the pixel, and determining a driving duration and a driving current of the pixel in a current frame includes:

Wherein M may be equal to or different from N, and the value of N may be greater than or equal to zero, which is not limited in the present invention, and when N is equal to zero, the same procedure is as in the above example. When N is not equal to zero, N and M may be, for example, 4 or 8, or 8 and 4, respectively, and the related technicians may perform calibration according to actual requirements.

Specifically, in the case where the values of the first N bits are all zero, the driving duration corresponding to the last M bits is equal to the driving duration corresponding to the last bit in the first N bits, and the driving current corresponding to each bit is sequentially reduced.

For example, the driving duration corresponding to the last bit in the first N bits is 2T, the total duration corresponding to the last M bits may be 2T, and if the driving current corresponding to the last M bits is 3/8I, the pixel point may be driven for 2T with a current of 3/8I.

The driving duration corresponding to the last N last bits may correspond to a minimum time for which the MOS transistor is fully opened, for example, equal to the minimum time or 1.2 times the minimum time, and so on.

In one possible embodiment, N is equal to 4 and m is equal to 4; under the condition that the values of the first N bits are all zero, the driving currents corresponding to the last M bits are sequentially 1/2I,1/4I,1/8I and 1/16I, and the driving time length corresponding to the last M bits is 1T.

Correspondingly, if the last M bits are 0001, the pixel point can be driven for 1T time with a current of 1/16I, and if the last M bits are 0110, the pixel point can be driven for 1T time with a current of 3/8I.

By adopting the scheme, the display data are divided, when the values corresponding to the first N bits are zero, the pixel points of the display are driven based on the driving currents corresponding to the last M bits, so that the problem that the low gray scale is difficult to distinguish due to insufficient opening of the MOS tube can be effectively avoided, and the display effect of the display is improved.

Wherein, M may be equal to N or different from N, and the value of N may be greater than zero, which is not limited in the present invention, when N is equal to zero, the scheme is the same as that in the related art, that is, when the number of M is greater, the driving duration corresponding to the last several bits may not enable the MOS transistor to be completely opened. N and M can be, for example, 4 or 8, or 8 and 4 respectively, and the related technicians can calibrate according to actual requirements.

Specifically, the driving time length corresponding to each bit in the first N bits of the display data is sequentially reduced, and the driving currents are the same;

For example, the driving duration corresponding to the first N bits is 2T, and the driving duration corresponding to the last M bits may be 3/8T, and then the pixel point may be driven for 2+3/8T with a current of 1I.

In one possible embodiment, N is equal to 4 and m is equal to 4; the driving time lengths corresponding to the first N bits are sequentially 8T,4T,2T and 1T, and the driving current is 1I;

Correspondingly, if the display data is 10000001, the pixel point 8+1/16T time period can be driven by a current of 1I, and if the display data is 00110110, the pixel point 3+3/8T time period can be driven by a current of 1I.

By adopting the scheme, the display data is divided, when any one of the values corresponding to the first N bits is not zero, the pixel is driven according to the total driving duration corresponding to the first N bits and the last M bits, the time length in the driving process corresponding to the display data is effectively ensured to be longer than the minimum time for fully opening the MOS tube, the problem that the low gray scale is difficult to distinguish due to insufficient opening of the MOS tube can be effectively avoided, and the display effect of the display is improved.

Optionally, the display is a Micro-LED (Micro Light Emitting Diode Display, micro light Emitting Diode) display, or a Micro-OLED (Micro Organic Light-Emitting Diode) display, or an AMOLED (Active-matrix organic light-Emitting Diode) display.

In order to make the specific embodiment of the above method more understood by those skilled in the art, the present invention further provides a schematic diagram of a driving unit shown in fig. 2, where the driving unit includes an SRAM (Static Random-Access Memory) 210 and a driving current source 220, as shown in fig. 2, where the SRAM210 may receive display data (i.e. Bit) based on a first input terminal and

the second receiving side receives the non-display data (i.e. Bit) and determines the driving time based on the display data, and the driving current source 220 is also able to determine the driving current based on the display data, e.g. 1/2I,1/4I,1/8I,1/16I, further steps involved in the above-described method embodiments. In addition, vss shown in fig. 2 represents ground, and Vcc indicates a high level.

Fig. 3 is a block diagram of a display driving apparatus according to an exemplary embodiment, and as shown in fig. 3, the display driving apparatus 30 includes:

a receiving module 31, configured to receive gray data to be displayed, where the gray data includes at least one frame of display data of one pixel point;

a determining module 32, configured to sequentially scan, for each pixel, display data corresponding to the pixel, and determine a driving duration and/or a driving current of the pixel in a current frame;

and a driving module 33, configured to drive each pixel according to the driving duration and/or the driving current, so as to display a gray scale corresponding to the display data.

Optionally, the determining module 32 is configured to:

Alternatively, N is equal to 4 and m is equal to 4;

Optionally, the display is a Micro light emitting diode Micro-LED display, or a Micro organic light emitting diode Micro-OLED display, or an active matrix organic light emitting diode AMOLED display. The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

The present invention also provides a computer readable storage medium having stored thereon computer program instructions which when executed by a processor implement the steps of the display driving method provided by the present invention.

Fig. 4 is a block diagram illustrating an apparatus 400 for display driving according to an exemplary embodiment. For example, apparatus 400 may be a mobile phone, computer, digital broadcast terminal, messaging device, game console, tablet device, medical device, exercise device, personal digital assistant, or the like.

Referring to fig. 4, apparatus 400 may include one or more of the following components: a processing component 402, a memory 404, a power component 406, a multimedia component 408, an audio component 410, an input/output (I/O) interface 412, a sensor component 414, and a communication component 416.

The processing component 402 generally controls the overall operation of the apparatus 400, such as operations associated with display, telephone calls, data communications, camera operations, and recording operations. The processing component 402 may include one or more processors 420 to execute instructions to perform all or part of the steps of the methods described above. Further, the processing component 402 can include one or more modules that facilitate interaction between the processing component 402 and other components. For example, the processing component 402 may include a multimedia module to facilitate interaction between the multimedia component 408 and the processing component 402.

Memory 404 is configured to store various types of data to support operations at apparatus 400. Examples of such data include instructions for any application or method operating on the apparatus 400, contact data, phonebook data, messages, pictures, videos, and the like. The memory 404 may be implemented by any type or combination of volatile or nonvolatile memory devices such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk.

The power component 406 provides power to the various components of the device 400. The power components 406 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power for the apparatus 400.

The multimedia component 408 includes a screen between the device 400 and the user that provides an output interface. The screen may be, for example, a Micro-LED (Micro Light Emitting Diode Display, micro-light Emitting Diode) display, or a Micro-OLED (Micro Organic Light-Emitting Diode), or an AMOLED (Active-matrix organic light-Emitting Diode) display. In some embodiments, the screen may further include a Touch Panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from a user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensor may sense not only the boundary of a touch or slide action, but also the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 408 includes a front camera and/or a rear camera. The front camera and/or the rear camera may receive external multimedia data when the apparatus 400 is in an operation mode, such as a photographing mode or a video mode. Each front camera and rear camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

The audio component 410 is configured to output and/or input audio signals. For example, the audio component 410 includes a Microphone (MIC) configured to receive external audio signals when the apparatus 400 is in an operational mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signals may be further stored in the memory 404 or transmitted via the communication component 416. In some embodiments, audio component 410 further includes a speaker for outputting audio signals.

The I/O interface 412 provides an interface between the processing component 402 and peripheral interface modules, which may be a keyboard, click wheel, buttons, etc. These buttons may include, but are not limited to: homepage button, volume button, start button, and lock button.

The sensor assembly 414 includes one or more sensors for providing status assessment of various aspects of the apparatus 400. For example, the sensor assembly 414 may detect the on/off state of the device 400, the relative positioning of the components, such as the display and keypad of the device 400, the sensor assembly 414 may also detect the change in position of the device 400 or a component of the device 400, the presence or absence of user contact with the device 400, the orientation or acceleration/deceleration of the device 400, and the change in temperature of the device 400. The sensor assembly 414 may include a proximity sensor configured to detect the presence of nearby objects in the absence of any physical contact. The sensor assembly 414 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 414 may also include an acceleration sensor, a gyroscopic sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

The communication component 416 is configured to facilitate communication between the apparatus 400 and other devices in a wired or wireless manner. The apparatus 400 may access a wireless network based on a communication standard, such as WiFi,2G or 3G, or a combination thereof. In one exemplary embodiment, the communication component 416 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 416 further includes a Near Field Communication (NFC) module to facilitate short range communications. For example, the NFC module may be implemented based on Radio Frequency Identification (RFID) technology, infrared data association (IrDA) technology, ultra Wideband (UWB) technology, bluetooth (BT) technology, and other technologies.

In an exemplary embodiment, the apparatus 400 may be implemented by one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital Signal Processing Devices (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic elements for executing the methods described above.

In an exemplary embodiment, a non-transitory computer-readable storage medium is also provided, such as memory 404, including instructions executable by processor 420 of apparatus 400 to perform the above-described method. For example, the non-transitory computer readable storage medium may be ROM, random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, etc.

In another exemplary embodiment, a computer program product is also provided, comprising a computer program executable by a programmable apparatus, the computer program having code portions for performing the above-described display driving method when executed by the programmable apparatus.

The above description is only illustrative of the preferred embodiments of the present invention and of the principles of the technology employed. It will be appreciated by persons skilled in the art that the scope of the disclosure referred to in the present invention is not limited to the specific combinations of technical features described above, but also covers other technical features formed by any combination of the technical features described above or their equivalents without departing from the spirit of the disclosure. Such as the above-mentioned features and the technical features disclosed in the present invention (but not limited to) having similar functions are replaced with each other.

Moreover, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the invention. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are example forms of implementing the claims. The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

Claims

1. A display driving method, comprising:

2. The method of claim 1, wherein the display data comprises a plurality of bits, each bit corresponding to a different drive duration and/or drive current.

3. The method according to claim 2, wherein sequentially scanning the display data corresponding to the pixel to determine the driving duration and/or the driving current of the pixel in the current frame comprises:

4. The method according to claim 2, wherein sequentially scanning the display data corresponding to the pixel to determine the driving duration and/or the driving current of the pixel in the current frame comprises:

5. A method according to claim 3, wherein, in the case where the values of the first N bits are all zero, the driving duration corresponding to the last M bits is equal to the driving duration corresponding to the last bit of the first N bits, and the driving current corresponding to each bit is sequentially decreased.

6. The method of claim 4, wherein the driving time period corresponding to each of the first N bits of the display data decreases in sequence, and the driving currents are the same;

7. A method according to claim 3, wherein N is equal to 4 and m is equal to 4;

8. The method of claim 4, wherein the driving durations corresponding to the first N bits are 8T,4T,2T, and 1T in order, and the driving current is 1I;

9. The method of any one of claims 1-8, wherein the display is a Micro light emitting diode Micro-LED display, or a Micro organic light emitting diode Micro-OLED display, or an active matrix organic light emitting diode AMOLED display.

10. A computer readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the steps of the method of any of claims 1-9.