SE516923C2 - The same screen is operated in two modes, which cannot be used simultaneously - Google Patents

Abstract

According to the present invention, in an electronics device having a display unit (11), the display unit (11) comprises according to the present invention at least two interfaces (38, 39), controlled by one display control unit (30, 31) each. The electronics device comprises further an arbitrator (42), resolving any access conflicts between the interfaces (30, 31). The arbitrator (42) can be implemented as a switching means in the display unit or as a software communication between the display control units. The interfaces (30; 31) preferably control mutually overlapping areas (40, 41) of the display unit (11). One of the interfaces (39) may be slow, and accessed e.g. by a serial connection, being responsible for the information display during stand-by or inactivity periods, when only limited information display is needed. During such periods, the display control device (31) for the other interface (38) and associated circuitry are preferably turned off. The other interface (38) is preferably of a fast type, accessed by e.g. a parallel connection, being responsible for a full utilization of the display unit (11).

Description

51-6 "923 2 ~ -«.....,. Operation, which saves the power requirement of the LCD device itself. The other instead reduces the number of pixels, which also reduces the power requirement of the LCD device.

By using devices according to the technique described above, the power requirement is considerably reduced. However, any further reductions in power consumption would be appreciated as it increases the life of a fully charged battery. As recent developments in telecommunications and computer devices require the presentation of more and more information, e.g. In mobile phones for Internet connections and advanced laptops, the display devices are often quite large and the processing power needed to provide the information to be displayed increases. These large display units and the connected processor units require more electrical power than e.g. small conventional mobile phones. Even with the power consumption of the technology for such devices too large. Therefore, there is a general need for the power reduction methods according to the position to further reduce the power consumption in portable electronic devices.

SUMMARY A general problem with portable electronic devices with displays according to the state of the art is an excessive power consumption in relation to the desired battery lives.

The general object of the present invention is therefore to reduce the power consumption of electronic devices which have information displays. A further object of the present invention is to reduce the power requirement during standby or inactivity periods. Another object of the present invention is to reduce the power consumption of equipment associated with the operation of the display unit, but not necessarily of the display unit itself.

S16 923 s u n »ø» | ø. . The above objects are achieved by devices and methods according to the appended claims. In general terms, in an electronic device having a display unit, the display unit according to the present invention comprises at least two interfaces, each controlled by a display control unit. The electronic device further comprises a mediator unit, which resolves any access points between the interfaces.

The mediator unit can be implemented as a switching means in the display unit or as a software communication between the display control units.

The interfaces preferably control overlapping areas on the display unit. One of the interfaces can be slow, ie. have a low bandwidth, and is accessible e.g. through a serial connection, which is responsible for the information display during standby or inactivity periods, when only limited information display is needed. During such periods, the display controller of the second interface and associated circuits are preferably turned off. The second interface is preferably of a fast type, i.e. has a large bandwidth, and is accessible through e.g. a parallel connection, which is responsible for a full utilization of the display unit.

The advantage of the present invention is that power consuming parts used to control the display unit in an active mode can be turned off during standby or inactivity periods, since the display control is then performed by a smaller power consuming alternative display control unit, with a separate interface.

Further advantages and features of the present invention will become apparent upon reading the following detailed description of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in which: 1016 523 923 4 o a u u o v o ». . FIG. 1 is an illustrative block diagram of an example of a prior art mobile telephone; FIG. 2 is a block diagram of an embodiment of a display device according to the present invention; FIG. 3 is a block diagram of another embodiment of a display device according to the present invention; FIG. 4a is a schematic drawing of a mobile telephone in a folded state; FIG. 4b is a schematic drawing of a mobile telephone in an open state; FIG. 4c is a schematic drawing of a part of the mobile telephone shown in Figs. 4a and 4b; FIG. 5 is a schematic drawing of a mobile telephone according to the present invention; FIG. 6 is a schematic drawing of a laptop computer according to the present invention; and FIG. 7 is a schematic drawing of a display unit according to the present invention; FIG. 8 is a display control method according to the present invention. Fate diagram illustrating a DETAILED DESCRIPTION OF EMBODIMENTS First, prior art devices will be discussed to clarify the characterizing features of the present invention which will be presented later. I fi g. 1 schematically illustrates an example of a mobile phone according to the prior art. This mobile phone is equipped to enable e.g. connection to an Internet network. A display device comprises a display unit 11, which is controlled by a display control unit 12, which in this example is part of a central processor unit (CPU) 13.

The display controller 12 is connected to an interface 14 of the display unit via a connection 15. The CPU 13 is used for processing the large amounts of information necessary for e.g. Internet access. The CPU .516 923 s 13 is connected to memory means 20, 21 as direct access memories. To communicate with any telecommunication network, the telephone is equipped with a radio unit 18 and an antenna 19 for transmitting and receiving radio signals. The radio unit is connected to a baseband control unit 17, which in turn is connected to the CPU 13. The interface 14 can be of different types, e.g. a sub-screen solution, where an active part of the display 16 can be changed from time to time, depending on the present operating mode.

In such a device there are four main objects that require electrical power; the radio unit 18, the baseband control unit 17, the CPU 13 with associated units and the display unit 11. The reduction of the power consumption of the display 11 is well developed, e.g. by using sub-screen solutions etc. The power consumption of the radio unit 18 is mainly determined by the efficiency of antenna functions, which will not be discussed further here. The baseband controller 17 has a relatively limited power consumption and does not require immediate attention. However, the CPU, especially for devices equipped for advanced tasks such as Internet access, needs a lot of electrical power. To reduce the total power consumption, the CPU is turned off during e.g. stand-by periods. However, to maintain a few simple information presentations, such as e.g. time, date, signal strength and / or battery charge status, the display unit must be activated regularly. This update of the stand-by information is normally performed by starting the CPU unit 13, delivering the necessary information to the display interface 14 and turning off the CPU 13 again.

However, such procedures normally also involve e.g. memories 20, 21, all of which together cost unreasonable amounts of power.

The basic idea of the present invention is to provide the display unit with an additional interface and control unit in order to have a display access that requires less power. This idea is applicable to all types of display electronic devices that have an active mode with intensive display operation and a stand-by mode with an economical display operation. To accomplish this, the display unit must be equipped with at least two 516 923; -,; --.-..- 6 s "š oo uno interfaces. There are LCD units today, which allow a choice to use the interface either as a serial or as a parallel interface, but these interfaces are mutually exclusive because the choice of interface is made at the physical connection of the hardware.

I fi g. 2 illustrates an embodiment of a display device 10 according to the present invention. The display device 10 comprises a display unit 11, preferably an LCD unit (fl surface-crystal display unit).

The display unit 11 comprises a first interface 39 and a second interface 38. The first interface 39 is connected to a first control unit via a first display connection 34 and the second interface 38 is connected to a second display control unit 31 via a second display connection 33.

The second display controller 31 is in the present embodiment implemented as part of a central processor unit (CPU) 32.

The controllers 30, 31 are preferably implemented by microprocessors.

The CPU 32 and the first display controller 30 are interconnected by an interconnect 37, and are both parts of the same processor unit 35, although they are independently operable parts. The first display control unit is provided with stand-by information via a connection 36. The origin of such stand-by information could be found within the processor unit 35, within the display device 10 or from an external source.

The first interface 39 of the display unit 11 is arranged to drive the display unit 11 in a first display mode, which has access to a first display area 41 on the display. The second interface 38 of the display unit 11 is similarly arranged to drive the display unit 11 in a second display mode, which has access to a second display area 41 on the display.

The first display area 41 and the second display area 40 are overlapping each other and preferably the first display area 41 forms a sub-area of the second display area 40.

Since each of the interfaces 38, 39 has its own display control unit 31, 30, a cone can be found when accessing the display unit 11. In order to 1016 923 7. . '. . . . . . .- resolving such conflicts, a mediator unit 42 is provided. In this embodiment, the mediator unit 42 is a dual switch controlled by the CPU 32.

When a high display activity is needed, the CPU 32 is intensively involved in processing the corresponding data. The second interface 38 is active and the large second display area 40 is used. The mediator unit 42 keeps the display connection 33 closed, and prevents any information på on the display connection 34. Some information can enter the stand-by information connection 36 and be processed by the CPU, before it is presented on the display through the second interface 38.

When a low activity or standby period occurs, the need for processing power is reduced. The need for a large display area is also reduced, as only a few parameters can be interesting to present. In such a case, the mediator unit 42 transfers responsibility for the display control to the first display control unit 30 and connects the first interface 39. The CPU 32 and the second display control unit 31 are turned off to reduce power consumption. During the stand-by period, only certain limited stand-by information is received via the connection 36. This stand-by information is received by the first display controller 30, which updates the display accordingly. This means that during the stand-by period, only the first low power consumption display controller 30 is active. When the standby period ends, the CPU 32 restarts, and resumes the display control function.

Since the first interface 39 is intended for use during periods of low activity. The first display connection 34 can therefore preferably be a serial connection with a relatively low transmission speed, i.e. a connection with small bandwidth. The first display area 41 is also preferably small, which thereby also requires power. partial screen solution is used. On the other hand, the second interface 38 reduces the display unit Preferably, one can be intended for use during periods of high activity. The requirements for transmitting display information are much larger, and the second connection 33 is therefore preferably a parallel connection, which offers a high information rate to the display unit, i.e. a connection with large bandwidth.

Accordingly, the second display area 40 is preferably larger than the first 41. Since there are no contexts in operating the display in the two modern ones, the areas 40, 41 may overlap each other, and preferably the second display area 40 will cover the entire first display area. 4 1, to use the maximum capacity of the display unit.

Fig. 3 illustrates another embodiment of a display device according to the present invention. Similar parts are marked with the same reference number and are not discussed further. In this embodiment, the standby information is exemplified by the status of the power supply unit of the processor unit 35. A battery 45 is connected to a control unit 46, which provides an operating voltage Vad via a power supply connection 47 to the processor unit. A voltage level connection 48 transmits the voltage level of the battery 45 to an analog-to-digital converter 44 in the processor unit. The result is transmitted to the first display controller 30.

During high activity operation, this battery status information is passed to the CPU 32.

In the embodiment in fi g. 3, the mediator unit is provided as a switch 43 at the display unit 11. The switch alternately connects one of the interfaces 38, 39. The switch is preferably software controlled by e.g. The CPU 32 or the first display controller 30.

The display devices described above are advantageously used in various portable electronic devices. Figs. 4a-c schematically illustrate a mobile telephone 50 with functionality for Internet access. I fi g. 4a, the telephone 50 is illustrated in a folded configuration, where a base unit 51 is partially covered by a cover 52. A display device 53 is arranged on the front of the base unit 51. When the cover 52 is folded over the base unit 51, as illustrated in fi g. 4a, only a small first part 54 of the display is visible. In such a configuration, 10 can. _jlf51'69 92 3 the phone is used as a standard mobile phone, and the first part 54 of the display unit shows the necessary information. I fi g. 4b, the telephone 50 is folded up, by turning the cover 52 away from the base unit 51. The entire display area 55 of the display device 53 is visible and is available to show e.g. Internet information. I fi g. 4c shows the display part of the phone illustrated in fi g. 4a and 4b. In this figure, the first subarea 54 and the entire display area are drawn together, showing the differences in display preferences. Such a telephone will benefit greatly from having a display device according to the present invention.

I fi g. 5 illustrates a sketch of a mobile telephone according to the present invention. Similar parts as in previously described display devices have the same reference number and are not discussed further.

The baseband controller 17 is provided with a first display controller 30, connected by a first display connection 34 to a first interface 39 which controls a first area 54 of the display 11. The CPU 13 is as previously provided with a second display controller 31, connected by a second display connection 33 to a second interface 38 controlling a second area 55 on the display 11. In this embodiment, the mediator unit 60 is implemented as a software communication over the interconnection between the baseband controller 17 and the CPU 13, and manages the access rights to the interfaces 38, 39.

When the mobile telephone is operated in the Internet mode, the CPU 13 is fully utilized, the second display control unit 31 has control over the display 11 according to the communication of the mediator unit 60. The entire screen is drivable. When the mobile phone is folded and in standby mode, the only information that is normally displayed is the signal strength, the status of the battery charge and the time and date. The baseband controller provides this information easily. The CPU 13 is consequently switched off, and the mediator unit 60 hands over the display control to the first display control unit 30. Such switch-off of the main CPU 13 during periods of inactivity is known in the prior art. The smaller first area 54 of the display 11 is now available for the limited information required and the power consumption of the CPU 13 and the memories 20, 21 is now completely avoided.

A comparison of the phones in fi g. 1 and fi g. 5 will clearly show the essence of the present invention. The display is provided with two interfaces, which are driven by two independent display controllers 30, 31. One unit 31 is associated with a power consuming high activity processing unit 13, and has access to a large display area 55. The other 30 is independent of the power consuming high activity processor unit 13 and can therefore operate a smaller area 54 during low activity periods, thus reducing power consumption and extending battery life.

Fig. 6 illustrates another interesting device, which is advantageously provided with a display device according to the present invention. A laptop 70 includes a bottom portion 72 and an upper portion 71, which are foldable toward each other. The bottom part 72 is provided with keys, mouse functions, etc. according to the state of the art. The upper part is equipped with a large LCD screen 73. During normal operation, the entire screen area 74 is normally used to display the necessary information. The computer and the display operate in a high-power consuming mode. During inactivity periods, however, the only information that normally needs to be updated is the time and battery charge indicator, located in a limited screen area 75. In such a state, the main processor can be turned off, saving power, while a simple low power consuming display controller is made responsible for updating the standby information. .

Fig. 7 schematically illustrates a preferred embodiment of a display unit according to the present invention. An LCD unit 11 comprises an LCD area 53. A row drive unit 82 and a column drive unit 81 control the LCD area 53.

The column drive is included in a drive controller 80. A first interface 39 and a second interface 38 are the inputs to the drive controller 80.

The drive control unit further comprises a control block 89 and a display RAM 90. In this embodiment, the first interface 39 consists of a serial interface, which has a serial data input / output terminal 83 and a serial clock terminal 84. The second interface 38 in this embodiment consists of a parallel interface, which has a 16-bit bidirectional data bus 85, a signal connection for command / data selection 86, a read strobe connection 87 and a write strobe connection 88. The interfaces according to the present invention are thus simultaneously physically connectable, but are operated only one at a time . A mediator unit, implemented either in the display unit itself or in associated units, performs this mediation. In a preferred embodiment, a block 48 within the control block 89 performs the mediation.

Fig. 8 is a flow chart illustrating a display control method according to the present invention. The process starts in step 100. In step 102 a mediation process is done. Here it is decided whether the display should be operated in a first mode or not. If the first mode of operation is to be selected, a first display unit interface is operated in step 104, which drives the associated display in the first mode. However, if the first mode is not of interest, a second display unit interface is operated in step 106, which drives the associated display in a second mode. The process ends in step 108. The illustrated process should not be construed as a true fl fate diagram, but rather illustrates the alternating access to the two display modes.

As will be appreciated by those skilled in the art, there are fl your possible modifications and variations within the scope of the appended claims. For example, the principle of independently acting interfaces can be implemented on more than two interfaces, which adapts the display control to the activity level in your steps. One possible case would be the mobile phone shown earlier, where a first mode could be a pure stand-by mode, a second mode could be a normal phone mode and a third mode could be an Internet mode. These modes require different amounts of display area and different processing power. Those skilled in the art will recognize that various modifications and changes may be made to the present invention without departing from its scope, as defined by the appended claims.

Claims (36)

lO 15 20 25 30, 51s 92s H, n ,,,,,,, _, ß ru '-5 = .. =. =. . =. NEW PATENT CLAIMS Display device (10), having a display unit (11; 53; 73), characterized in that the display unit (11 1; 53; 73) comprises a display (53), drive units (81, 82) and at least a first (39 ) and a second interface (38) both connected to the same drives (81, 82), the first interface (39) being connected to a first display controller (30) and the second interface (38) being connected to a second display controller ( 31), and a mediator unit (42; 43; 48; 60), which mediates between said interfaces (38, 39). Display device according to claim 1, characterized! that the mediator unit is a software-controlled mediator unit (42; 43; 48; 60). Display device according to claim 2, characterized in that the mediator unit is a switch (43) at the display unit (1 1; 53; 73). Display device according to claim 2, characterized in that the mediator unit comprises (60) between the display control units (30, 3 1). communication body Display device according to one of Claims 1 to 4, characterized in that the interfaces (38, 39) control overlapping areas (40, 41; 53, 54; 74, 75) on the display unit (1 1; 53; 7 3). Display device according to one of Claims 1 to 5, characterized in that the first interface (39) is a low-bandwidth interface. Display device according to claim 6, characterized in that the first interface (39) is a serial interface. Display device according to one of Claims 1 to 7, characterized in that the second interface (38) is a large-bandwidth interface. 10 15 20 25 30 4516 923 '"° u nu nu..... - - ~ 1' 2". . g - - 1 I - I I _ _,, z "'.: 2 I' i - - - -, .I u n u» o ~ n ~ - o ou 'UI 0 Display device according to claim 8, characterized in that the second interface (38) is a parallel interface. Display device according to one of Claims 1 to 9, characterized in that the second display control unit (31) and associated means are switched off during periods of inactivity. Display device according to one of Claims 1 to 10, characterized in that at least one of the display control units (30, 31) is implemented by a microprocessor. Display device according to Claim 1 1, characterized in that the display control units (30, 31) are implemented as independent means by the same processor unit (35). Display device according to one of Claims 1 to 12, characterized in that the display unit (11; 53; 73) is a surface crystal display. Display device according to one of Claims 1 to 13, characterized in that the first interface (39) is arranged to drive the display unit (11; 53; 7 3) in a partial screen mode. Portable electronic device (50, 70), having a display unit (11; 53; 73), characterized in that the display unit (11; 53; 73) comprises a display (53), drive units (81, 82) and at least a first (39) and a second interface (38) both connected to the same drive units (81, 82), the first interface (39) being connected to a first display controller (30) and the second interface (38) being connected to a second display controller (31), and a mediator unit (42; 43; 48; 60), which mediates between said interfaces (38, 39). 10 15 20 25 30 115161923 n u u u .. u - g n v u n u: u v f. U. O vc OI. . . -. -. - -. . . . - Ill IDO I) I I I I U I I I I I Ü. . . n .u u o c I - I 0 E -. . n u .u u u »H I Portable electronic device according to claim 15, characterized in that the mediator unit is a software-controlled mediator unit (42; 43; 48; 60). Portable electronic device according to claim 16, characterized in that the mediator unit is a switch (43) at the display unit. Portable electronic device according to claim 16, characterized in! in that the mediator unit comprises communication means (60) between the display control units (30, 31). Portable electronic device according to one of Claims 15 to 18, characterized in that the interfaces (38, 39) control overlapping areas (40, 41; 53, 54; 74, 75) of the display unit (11; 53; 73). Portable electronic device according to one of Claims 15 to 19, characterized in that the first interface (39) is a low-bandwidth interface. Portable electronic device according to claim 20, characterized in! in that the first interface (39) is a serial interface. Portable electronic device according to one of Claims 15 to 21, characterized in that the second interface (38) is a large-bandwidth interface. Portable electronic device according to claim 22, characterized in that the second interface (38) is a parallel interface. Portable electronic device according to one of Claims 15 to 23, characterized in that the second display control unit (31) is switched off during periods of inactivity. 10 15 20 25 30 516 923 lb o. Up: Portable electronic device according to one of Claims 15 to 24, characterized in that at least one of the display controllers (30, 31) is implemented by a microprocessor. Portable electronic device according to claim 25, characterized in that the display control units (30, 31) are implemented as independent means by the same processor unit (35). Portable electronic device according to one of Claims 15 to 26, characterized in that the display unit (11; 53; 73) is a surface crystal display. Portable electronic device according to one of Claims 15 to 27, characterized in that the first interface (39) is arranged for driving the display unit (11; 53; 73) in a partial screen mode. A method of display control, comprising the steps of: operating a display unit (11; 53; 73) having a display (53) and drive units (81, 82), in a first mode through a first display control means (30) via a first interface (39); operating the display unit (1 1; 53; 73) in a second mode through a second display controller (31) via a second interface (38); to mediate between the first and second modems, A method according to claim 29, characterized by the further step: in switching off the second display control means (31) when the display unit (1 1; 53; 7 3) is operated in the first mode. Method according to claim 29 or 30, characterized in that the first and second moderns comprise overlapping areas (40, 41; 53, 54; 74, 75) on the display unit (11; 53; 73). 10 15 20 Method according to claims 29, 30 or 31, characterized in that the first mode comprises a partial screen mode. A method according to any one of claims 29 to 32, characterized in that the mediation step comprises the step of switching from the first mode to the second mode when the second display control means (31) has been inactive for a predetermined period of time. A liquid crystal display unit (1 1; 53; 73), comprising a display (53) and drive units (81, 82), characterized by at least two, simultaneously physically connectable, interfaces (38; 39), both interfaces (38; 39) are connected to the same drives (81, 82). Liquid crystal display according to Claim 34, characterized in that the interfaces (38; 39) are alternately accessible. Liquid-crystal display according to Claim 34 or 35, characterized in that the interfaces (38; 39) control overlapping liquid-crystal display areas (40, 41; 53, 54; 74, 75).