JP4749216B2 - Method and apparatus for controlling power of wireless communication terminal - Google Patents

Description

  The present invention relates to a method and apparatus for controlling the power of a wireless communication terminal, and more particularly, to lighting control of an image display apparatus and RF signal transmission power control in a wireless communication terminal.

  In recent years, digital wireless communication technology has advanced remarkably, and various wireless communication terminal services such as mobile phones, videophones, video conference systems, and video surveillance systems have been used. Radio communication technology has been actively developed in response to generational demands and has been standardized as a radio communication system.

  In particular, in the communication standard for mobile phones, the development of communication methods or communication systems is remarkably progressing, and it is classified as several generations. The first generation mobile phone is an analog mobile phone that employs frequency division multiple access (FDMA), and is mainly used as a car phone. Cellular phones of 2nd generation and later have been digitized for wireless communications, improving frequency utilization efficiency, and 2nd generation time division duplex (TDMA) / frequency division duplex (FDD) Duplex) PDC (Personal Digital Cellular) communication standard and Code Division Multiple Access (CDMA) / FDD cdmaOne (or CDMA2000) communication standard called 2.5th generation. Other European standards include GSM (Global System for Mobile Communications), and it has become a generation that transforms the functions of mobile phones from telephone calls to data communications.

  The 2.5th generation to 3rd generation mobile phones employ a CDMA system to improve low-noise calls and handoff when the mobile phone is moving, thereby enabling high-speed communication. The International Telecommunication Union (ITU) has established a standard for 3rd generation wireless communication as “IMT-2000”, which includes time division duplex-code division multiple access (TD). -CDMA: Time Division-Code Division Multiple Access (TDD), Wideband Code Division Multiple Access (W-CDMA) / FDD, and CDMA2000, which is a higher standard of the cdmaOne standard. .

  The TDMA system is a system that is shared by a plurality of users while being divided by time slots at the same frequency. The CDMA system is a system in which a large number of users can use a plurality of channels simultaneously at the same frequency, and a partner is identified by a code (also referred to as a code). The TDD (Time Division Duplex) method is a communication method that uses the same frequency and separates the time for transmission and reception. The FDD (Frequency Division Duplex) method is a communication method in which a frequency band is divided into transmission and reception and simultaneous transmission / reception is performed.

  The technical specifications included in the “CDMA2000” standard include a plurality of specifications. One of them is the “1xEV” communication method using one 1.25MHz band, and the “1xEV” communication method includes “1xMC”, “1xEV-DV”, “1xEV-DO”, etc. ( When you simply say “1x”, it is common to say “1xMC”). There is also "3x MC" that bundles three 1.25MHz bands and operates as one channel. Furthermore, the technical specifications included in the CDMA2000 standard include the 1xEV-DO, an additional standard for CDMA2000, that enables high-speed data communication close to the broadband of terrestrial communication services, and the 1xMC As part of the "1xEV" specification with improved specifications, there are "1xEV-DO" specialized for data communication and "1xEV-DV" compatible with both voice and data communication.

  Mobile phone services that have taken a step forward from the 3rd generation have high-speed communication as HSDPA (High Speed Downlink Packet Access) standards and WiMAX (Worldwide Interoperability for Microwave Access, IEEE 802.16a) standards in order to build higher-quality wireless communication networks. Has been put to practical use. In recent years, broadband services using mobile phones have also been provided. As described above, services using mobile phones are diversified, and higher speed and higher quality are required.

  “IBurst” has been proposed as a next-generation wireless communication technology, and iBurst is a TDMA / TDD wireless communication method positioned as an advanced PHS. Frequency utilization efficiency has been improved compared to the 3rd generation communication method, and it has been transformed into a powerful communication system that can be called a "high-speed data communication type mobile phone" that cannot be compared with the PHS used in the 2nd generation. .

  As a result of these diverse communication standards, wireless communication terminals not only improve high-speed communication, wide bandwidth, and high quality, but also improve communication sustainability, operability, and usability of image display devices as wireless communication terminals. The fact is that it is spreading.

  In particular, even if attention is paid to the image display device of a wireless communication terminal, the communication sustainability, operability, screen display, etc. are more user-friendly and as a terminal that can withstand advanced communication standards. Enhancement of usability is desired.

  Typical image display devices (ie, light emitting means) used in wireless communication terminals include liquid crystal panel display devices (LCD), plasma display devices (PDP), field emission display devices (FED), organic・ Inorganic electroluminescence (EL).

  In general, an LCD has a display function by polarizing and modulating light from a backlight using a light emitting diode or a cold cathode lamp using a plurality of polarizing plates. An active matrix liquid crystal panel using a thin film transistor (TFT) is mainly used.

  In general, a PDP has two glass plates (that is, display panel portions) filled with a rare gas such as neon or xenon provided with electrodes arranged in rows so as to oppose each other. The intersecting point is configured as a light emitting element portion. By selectively applying a voltage to the specific light emitting element part, ultraviolet rays are generated from the sealed gas, and secondary electrons resulting from the ultraviolet rays collide with the phosphor applied or pasted on the display panel part. It emits light and has a display function.

  In general, the FED forms a light emitting element portion by applying or attaching a phosphor to the inside of a display panel on the display side of a pair of display panels and providing a field emission cathode on the other display panel. The field emission cathode further has a field emission type microcathode of minute size, and the emitted light is accelerated by irradiating the electron emitted from the microcathode by applying an electric field to the phosphor to excite the light emission. It has a display function.

  An EL display device is called electroluminescence (EL) because it emits light by colliding energy excited by an electric field with a phosphor material, and a light emitting element portion is formed by forming an electrode portion with a two-dimensional matrix. . For phosphor materials, those that use organic substances such as diamines are called organic EL, and those that use inorganic substances such as zinc sulfide are called inorganic EL. Among these, inorganic EL currently has a problem in spectral characteristics, and it is an image display device using organic EL that has been put into practical use. Since the organic EL is a self-luminous type, the viewing angle dependency is not a problem, and has advantages such as high luminance, low voltage driving, and full color.

  Various display devices as described above are disclosed as conventional techniques (for example, Patent Document 1).

  By the way, the image display device as described above can be used in the image display device of the wireless communication terminal. However, it is preferable that the backlight of the image display device is essentially turned on with no variation in brightness. It is also known that the user feels visually dark by repeating lighting on / off. That is, when no special point collation control and / or transmission power control is performed between turning on / off the backlight and whether or not the RF signal is transmitted, the light is turned on when the RF signal is transmitted. It becomes dark to repeat on / off, and brightens to keep lighting on when not transmitting RF signal.

  As a result, brightness variation can occur depending on whether or not an RF signal is transmitted, even though the same screen is displayed. Such a situation can also occur depending on the transmission rate.

  Furthermore, if an RF signal is transmitted while the OLED is on, the current consumption of the wireless communication terminal may increase significantly, and in that case there will be an instantaneous voltage effect. May occur. This instantaneous voltage drop may be erroneously detected as a low battery by the CPU provided in the wireless communication terminal, and the wireless communication terminal may be shut down.

  Therefore, a prior art for improving the usability of the backlight is disclosed (for example, Patent Document 2). According to the prior art, the backlight lighting control timing and the RF signal transmission on / off control timing are synchronized, and when the RF signal transmission is on, the backlight is lit off, and the RF signal transmission is off. Sometimes the backlight is turned on. According to this technology, even if lighting is turned on / off, control is performed so as to maintain a certain level of brightness, thereby ensuring visibility.

  Also, when the transmission power is on, the backlight is turned on so that the periodic voltage drop of the circuit voltage of the wireless device terminal due to the RF signal transmission burst is minimized while the backlight of the image display device is lit. Is controlled to turn off. As a result, the lighting of the display unit backlight (or light emitting element) and the transmission power of the transmission power do not occur at the same time, so there is no voltage drop in the circuit of the wireless device terminal and the battery of the wireless device terminal Also has the advantage of long lasting.

JP2004-205974 JP 9-261168

  However, according to the lighting control according to the prior art described in Patent Document 2, it is synchronized with the timing of RF signal transmission on / off control, the backlight is turned off when the RF signal transmission is on, and the RF signal transmission is off. At this time, since the backlight is only controlled to be turned on, the lighting on / off duty ratio in the display screen is irregularly controlled, so that a stable brightness of the display device cannot be obtained. .

  In addition, if the third generation or next generation communication standards are taken into account, it is expected that the occurrence rate of the above-mentioned problem due to temporal fluctuations in the transmission rate or the information amount will increase, and in the prior art described in Patent Document 2, Even if it exists, it is a problem which cannot be solved, and it is desired to perform lighting control and / or transmission power control suitable for a more suitable wireless communication terminal.

  An object of the present invention is to provide a lighting control method and transmission power control method for an image display device, a lighting control device, and a wireless communication terminal including the image display device, which solve this problem.

  The wireless communication terminal according to the present invention includes display means having light emitting means and a transmission circuit having a power amplifier that turns transmission on / off in accordance with transmission timing. Further, a luminance control means for controlling on / off of the light emitting means at a cycle according to the required luminance of the display means, and transmission on of the power amplifier within the on period of the light emitting means under the control of the luminance control means. Power control means for turning off the light emitting means in response to the power control means, and a time measuring means for measuring the time when the light emitting means is turned off by the power control means, the luminance control means, the light emitting means is off, In addition, the light emitting unit is turned on only for a time measured by the time measuring unit during a period in which the power amplifier is in a transmission off state.

  Still another wireless communication terminal according to the present invention includes a display unit having a light emitting unit and a transmission circuit having a power amplifier that turns on / off transmission according to a transmission timing, and has a cycle according to a required luminance of the display unit. Luminance control means for turning on / off the light emitting means, and power control means for turning off the light emitting means when the transmission power of the transmission circuit exceeds a predetermined value during the on period of the light emitting means controlled by the luminance control means; And time measuring means for measuring the time when the light emitting means is turned off by the power control means. The luminance control means turns on the light emitting means for a time counted by the time measuring means during a period in which the light emitting means is turned off and the power amplifier is turned off.

  As another aspect, a power control method for a wireless communication terminal according to the present invention comprises: a display unit having a light emitting unit that is turned on / off at a cycle according to a required luminance; In the power control method for a wireless communication terminal, the step of turning off the light emitting means when the transmission means is on during the on period of the light emitting means based on the period, and the turning on of the light emitting means based on the period. Integrating the time during which the light emitting means is turned off during the period, and turning on the light emitting means for the accumulated time when the transmission means is off during the off period of the light emitting means based on the period. And a step of performing.

  As yet another aspect, a power control method for a wireless communication terminal according to the present invention includes a display unit having a light emitting unit that is turned on / off in a cycle according to a required luminance, and a transmission unit that turns on / off transmission according to a transmission timing. In a power control method for a wireless communication terminal comprising: turning off the light emitting means when the transmission power of the transmitting means exceeds a predetermined value during the ON period of the light emitting means based on the cycle; and based on the cycle Integrating the time when the light emitting means is turned off in the on period of the light emitting means, and when the transmission means is transmission off during the off period of the light emitting means based on the period, only the accumulated time And turning on the light emitting means.

  According to the present invention, since it is possible to have a configuration in which lighting of the backlight (or light emitting element) of the display device is not turned on and transmission of transmission power is not simultaneously generated, iBurst which is an FDD method of high-speed data communication method, CDMA2000 Even in the communication system of the communication standard, the voltage drop of the circuit of the wireless communication terminal does not occur and the battery lasts longer. Moreover, since only the lighting control and / or transmission power control is performed and the transmission timing of the RF signal is not changed, the communication standard can be observed.

  In addition, by keeping the duty ratio of lighting on / off of the light emitting element used for the light emitting means constant, the display unit of the display device can be kept in a stable brightness depending on whether the RF signal is transmitted or not. It can be displayed.

  Further, since it is possible to prevent the backlight (or light emitting element) of the display device from being turned on and transmission power from being transmitted on at the same time, no instantaneous large current flows. Therefore, a voltage drop in the circuit of the wireless communication terminal due to an instantaneous large current does not occur, and erroneous detection of a low battery is eliminated. As a result, the wireless communication terminal can be used for a longer time.

  First, a wireless communication terminal according to the present invention will be described.

  FIG. 1 shows a block diagram of a wireless communication terminal according to the present invention. The wireless communication terminal includes a CPU 101, a memory 102, an RF block 103, a display panel control unit 104, a battery 107, and a display device 110. Examples of the wireless communication terminal include a mobile phone and a video conference system transceiver.

  The CPU 101 is a central processing unit that controls the entire wireless communication terminal. Accordingly, the display state of the memory 102, the RF block 103, the display panel control unit 104, the battery 107, the display device 110, and the like can be monitored or controlled in an integrated manner.

  The memory 102 is a storage element unit that stores a control program or various data in the wireless communication terminal, is connected to the CPU 101 via a memory bus, and is used for various controls. The memory 102 can be built in the CPU 101 or can be constituted by a plurality of memories.

  The RF block 103 is a wireless communication driver unit capable of transmitting and receiving for performing wireless communication, and includes a control IC that transmits and receives wireless signals (that is, RF signals), a transmission power amplifier (hereinafter also referred to as PA), and the like. .

Generally, when an RF (Radio Frequency) signal S _RF of the RF block 103 is received via the antenna 111, the CPU 101 controls the frequency conversion (that is, demodulation) into an IF (Intermediate Frequency) signal. Signal processing. The CPU 101 extracts frame data as digital information from the IF signal. Under the predetermined control of the CPU 101, the extracted frame data is transferred to the display control unit 104. In the display panel control unit 104, the frame data is stored in the frame buffer 108 or processed as appropriate.

  In addition, when transmitting frame data to the outside of the wireless communication terminal (for example, a base station in the communication area of the wireless communication terminal), the IF signal is primarily modulated in the RF block 103 by predetermined control of the CPU 101. Then, secondary modulation is performed based on a predetermined communication standard, and finally transmission is performed as an RF signal via the antenna 111 with a requested transmission power from the base station (for example, based on IEEE802.11). In order to transmit as an RF signal, the RF signal is amplified by a power amplifier (PA).

  Further, the CPU 101 can control the transmission power value of the power amplifier (PA) by transmitting the transmission power control signal Sp to the RF block 103. Such a transmission power value control means may be configured as a transmission power control device instead of a CPU (not shown).

  For the sake of convenience, the RF signal transmission / reception control between the CPU 101 and the RF block 103 has been described as described above, but there are various types depending on the communication standard, the configuration content of the radio communication terminal, or the usage mode of the radio communication terminal. It will be apparent to those skilled in the art that the following configuration can be realized.

  The display panel control unit 104 includes a frame buffer 108, a brightness control unit 109 that controls power supply to the display device 110, and the like. The frame buffer 108 accumulates frame data and transmits the frame data to the display device 110 based on predetermined control by the CPU 101. The brightness control unit 109 transmits the RF signal transmission power level information Dtp via the CPU 101, the power amplifier (PA) on / off information Dop in the RF block, and the frame column row address information Dfa from the frame buffer 108. And a brightness for controlling the brightness of a backlight (not shown) provided in the display device 110 or a light emitting element (not shown) included in the display panel in accordance with a control method to be described later based on the information. The control signal Id is output. In order to operate transmission power control described later, the brightness control signal Id is also output to an input port provided in the CPU 101, for example.

  Further, the brightness control unit 109 has means for integrating the lighting on time or the lighting off time of the backlight or the light emitting element. Note that the means for accumulating such lighting on time or lighting off time can also be realized by the CPU 101. For example, the CPU 101 may calculate the integration time by detecting the calculation result by the brightness control unit 109 or the brightness control signal Id, and transmit the integration time information to the brightness control unit 109.

  The display device 110 includes at least a display panel 105 that displays various screens and a power supply unit 106 of the display panel. The display panel 105 receives frame data from the display panel control unit 104, and performs display corresponding to the frame data according to predetermined control or control described later. The power supply unit 106 of the display panel receives the signal Id from the brightness control unit 109 and controls the backlight or display so as to control the brightness of the display panel 105 (that is, the brightness of the backlight or the light emitting element). The power supply amount (or lighting voltage level or lighting time) of the light emitting elements configured in the panel is controlled. For example, when the display panel is an organic EL panel, based on the control signal Id from the brightness control unit 109, the lighting on / off time (that is, the lighting duty ratio) of the light emitting elements constituting the organic EL panel is set. The brightness of the display panel can be changed or adjusted.

  The battery 107 is a power supply source that supplies power to the entire wireless communication terminal. As the battery, a single cell lithium ion / lithium polymer battery or the like is generally used. Here, in FIG. 1, only the power supply Pd having relevance for brightness control in the display device 105 is shown. The relevance to such brightness control will become clear from the following description. In addition, as a power supply source of the wireless communication terminal, there are an external power supply type, a battery supply type, or a combination type of external power supply and battery supply, but the battery 107 is intended for a battery or when the battery is used. It is distinguished from an external power supply type wireless communication terminal. However, when the effects of the present invention can be obtained, the external power supply type may be used, or the battery 107 may be replaced with a fuel cell, an alkaline battery, a nickel cadmium battery, etc. It is not the subject of the present invention.

  Further, the CPU 101 monitors the supply voltage (hereinafter also referred to as battery voltage) of the battery 107 (Dpm in the figure). When the battery voltage falls below a predetermined threshold value, the CPU 101 wirelessly protects the wireless communication terminal. Control the entire signaling terminal to shut down. Specifically, the protection of the wireless communication terminal means preventing accidental erasure of memory data. Hereinafter, the predetermined threshold value of the battery voltage is also referred to as a low battery value, and the low battery value can be set to, for example, 3.4V. Further, the low battery value monitoring method by the CPU 101 can be realized by simply connecting the battery voltage or the resistance divided value of the battery voltage to the input port of the CPU 101. Alternatively, a well-known power management chip or a battery management chip can be used, and the low battery value monitoring method is not the subject of the present invention.

  Next, a case where the display device 110 uses a display panel including a plurality of light emitting elements configured by a matrix of column rows will be described.

  FIG. 2 is a control block diagram of a display panel including a plurality of light emitting elements configured by a matrix of column rows. The display device 110 includes a display panel control signal generation unit 401, a display panel control unit 402, a display unit 403, a column electrode signal driver 404, a row electrode signal driver 405, and a power supply unit. Referring to FIG. 1, the display panel 105 includes a display panel control signal generation unit 401, a display panel control unit 402, a display unit 403, a column electrode signal driver 404, and a row electrode signal driver 405. With.

  The display panel control signal generation unit 401 receives the display data signal fd and displays the voltage of each light emitting element provided in the display unit 403 (which may be a current depending on the type of the display panel) that can be individually controlled. A panel control signal is generated and output to the display panel control unit 402. The display panel control signal includes, for example, a vertical synchronization signal, a horizontal synchronization signal, and a synchronization clock.

  The display panel control unit 402 inputs a display panel control signal, and individually controls the voltage (which may be a current depending on the type of the display panel) of each light emitting element configured by a column row matrix provided in the display unit 403. Therefore, the column electrode signal and the row electrode signal are generated and output to the column electrode signal driver 404 and the row electrode signal driver 405, respectively.

The display unit 403 includes a plurality of light emitting elements configured by a column row matrix. Retsugyo matrix can identify the address of each light emitting element by electrode wire (shown _{r 1, r 2, ... r} n and shown _{c 1, c 2, ... c} m). Light emission of the light emitting element corresponding to a desired address is selectively controlled by the column electrode signal driver 404 and the row electrode signal driver 405. The light emission control of the light emitting element is, for example, a liquid crystal type light emitting element or an organic EL type light emitting element, and controls the voltage of the electrodes constituting the light emitting element. Further, for example, in the case of a light emitting diode type light emitting element, the voltage of an electrode constituting the light emitting element or the current flowing through the light emitting element is controlled.

  The power supply unit 106 is a power supply unit that supplies power to each component in the display device 110, but can supply a different voltage level for each component. For this reason, a voltage suitable for each component can be supplied, and a pump voltage may be used depending on the application. The voltage supplied to the display unit 403 can also be defined by voltage levels by the column electrode signal driver 404 and the row electrode signal driver 405. Moreover, only the brightness of the light emitting elements in a specific region in the display unit 403 can be made different by repeatedly turning on and off the voltage application by these signal drivers at a predetermined duty ratio.

  FIG. 3 shows an example in the case of specifying a column row address of the display unit 403 provided with a plurality of light emitting elements configured in a column row matrix. In FIG. 3, when it is desired to make the brightness of the display panel different between the main display unit 403a and the sub display unit 403b, as described in FIG. 2, the column electrode signal driver 404 and the row electrode signal driver 405 are used. By applying the voltage of the electrode of the light emitting element part constituting the main display part 403a, it is possible to display brightly (hereinafter also referred to as lighting on), and without applying the voltage of the electrode of the light emitting element part constituting the sub display part 403b. It can also be displayed darkly (hereinafter also referred to as “lighting off”). Alternatively, the brightness of the main display portion 403a and the sub display portion 403b can be made different by repeating lighting on / off with a predetermined duty ratio.

  Next, as Example 1, a lighting control method for an organic EL light-emitting element constituting a display panel of a wireless communication terminal according to the present invention will be described.

Example 1
FIG. 4 shows a flowchart for controlling lighting of the organic EL light-emitting elements constituting the display panel of the wireless communication terminal according to the present invention. It is assumed that an application such as a videophone is displayed on the organic EL screen in advance. In S201, it is assumed that the wireless communication terminal starts transmitting an RF signal.

  In S202, it is determined whether or not it is time to turn on the organic EL light emitting element. If it is not the timing to turn on the lighting, the process waits until the lighting is turned on (that is, loops in S202). If it is determined in S202 that it is time to turn on the light, it is determined in S203 whether or not the power amplifier (PA) is turned on. The method for determining whether or not it is the timing to turn on the lighting is based only on whether or not it is the lighting on timing for turning on the light at a predetermined cycle.

  If the transmission of the power amplifier (PA) is turned on in S203, the lighting of the organic EL light emitting element is turned off in S204, and the process returns to S203. Wait for the power amplifier (PA) to turn off transmission with the light off.

  If the power amplifier (PA) is off in S203, the organic EL light emitting element is turned on in S205. In S206, the time during which the organic EL light emitting element is turned on is integrated. In S207, it is determined whether or not the accumulated time during which the organic EL is turned on in one frame exceeds a predetermined value. If not, the process returns to S203. If it exceeds the predetermined value, the organic EL is turned off in S208. In S209, the accumulated time during which the organic EL is turned on is reset and waits until the next frame. As a sequence, it restarts from the start.

  Next, the operation timing when the wireless communication terminal is controlled based on the lighting control method of the organic EL light emitting element described in FIG. 4 will be described.

  FIG. 5 is a timing chart showing the relationship between the lighting of the organic EL light-emitting element of Example 1 and the transmission of an RF signal in the power amplifier (PA). FIG. 5 (a) is a timing chart of the prior art. In FIG. 5 (a), the time T + T ′ is constant for the lighting on time T of the organic EL light emitting element and the lighting off time T ′ of the organic EL light emitting element, for example, 20 ms. The timing at which the organic EL light emitting element is turned on and the timing at which the power amplifier (PA) is turned on are completely asynchronous. That is, as is apparent from FIG. 5 (a), there is a period in which both the lighting on timing of the organic EL light emitting element and the transmission on timing of the power amplifier (PA) overlap. During the ON period, the current flowing in the entire wireless communication terminal becomes a large current, and a battery voltage drop occurs. Such a voltage drop of the battery voltage is related to the quality of the entire wireless communication terminal, and has an adverse effect such as excessive consumption of the battery accumulated charge and brightness fluctuation of the display panel.

FIG. 5B is a timing chart of the first embodiment according to the method described in FIG. According to the method of the first embodiment, the organic EL light emitting element is turned off during the period of Tb ₁ and the organic EL light emitting element is turned on and the power amplifier (PA) is not turned on at the same time. Incidentally, since the organic EL type light emitting element is turned off by detecting the transmission on of the power amplifier (PA), it may be established at the same time, but it goes without saying that the effect of this embodiment can be sufficiently ignored.

That is, according to the prior art, the organic EL light emitting element is turned off even during the period when the organic EL light emitting element is turned on (that is, Tb ₁ ). Therefore, since the duty ratio of lighting on / off cannot be maintained at 1/1, in the present invention, the ON time of the organic EL light emitting element before the organic EL light emitting element is turned off is integrated, After the power amplifier (PA) transmits off the accumulated time, the organic EL light-emitting element is turned on during the Ta ₂ period. At this time, the on-time Ta ₁ of the organic EL light-emitting element and the on-time Ta ₂ of the organic EL light-emitting element are controlled so that T = Ta ₁ + Ta ₂ holds. Thus, by controlling the duty ratio of lighting on / off between T + T ′ to be constant, it is possible to configure a wireless communication terminal with stable quality without causing voltage fluctuations as in the prior art. it can.

Similarly, in FIG. 5 (b), in the period of Tb ₂ to the power amplifier (PA) is turned on, the organic EL light-emitting device is a lighting off, the organic EL light-emitting device for a period of Tb ₂ ' Turn on the light. The lighting time of the organic EL light-emitting element is controlled so that the lighting ON / OFF duty ratio between T + T ′ is constant.

  This control is particularly effective in a system that turns on / off the transmission of an RF signal at a constant cycle, such as the TDD method, such as PHS, PDC, and iBurst. In the PDC system, even if the transmission / reception switching rate is full, the transmission ON / OFF duty ratio is 1/3, and the brightness ON period of the organic EL light-emitting element is about 30% at maximum. It becomes. The time T + T ′ is constant. For example, if it is 50 Hz, the fluctuation of the ON / OFF time during that time does not cause any trouble in the visual action of the user.

  If configured as in the first embodiment, the lighting on of the backlight (or the light emitting element) of the display device and the transmission on of the transmission power do not occur at the same time. The voltage drop of the communication terminal circuit does not occur and the battery lasts longer. Moreover, since only the lighting control and / or transmission power control is performed and the transmission timing of the RF signal is not changed, the communication standard can be observed. Also, the same brightness can be displayed on the same screen of the display device when the RF signal is transmitted and when it is not transmitted.

  Next, as Example 2, a lighting control method for an organic EL light-emitting element constituting a display panel of a wireless communication terminal according to the present invention will be described.

(Example 2)
FIG. 6 shows a flowchart for controlling lighting of the organic EL light-emitting elements constituting the display panel of the wireless communication terminal according to the present invention. According to this embodiment, only when the transmission power of the RF signal is used as a trigger and transmission is performed with a transmission power equal to or higher than a predetermined threshold, that is, when more current is consumed in the wireless communication terminal, the organic EL light emission The lighting of the element can be controlled. Assume that the wireless communication terminal starts transmission control in S401. In S402, it is determined whether or not the timing for turning on the organic EL light emitting element is reached. If it is not the timing for turning on the light, the process waits until the lighting is turned on. The method for determining whether or not it is the timing to turn on the lighting is based only on whether or not it is the lighting on timing for turning on the light at a predetermined cycle.

  If it is time to turn on in S402, it is determined in S403 whether or not the transmission power request from the base station is a predetermined value (for example, 22 dBm) or more.

  In S403, when the transmission is performed with the transmission power equal to or higher than the predetermined value, the organic EL light emitting element is turned off and the process returns to S403 in S404. In S403, when transmitting with a power value less than the predetermined value, the organic EL light emitting element is turned on in S405.

  In S406, the time during which the organic EL light emitting element is turned on is integrated. In S407, it is determined whether or not the accumulated time during which the organic EL light emitting element is turned on in one frame exceeds a predetermined value. If not, the process returns to S403.

  If the predetermined value is exceeded in S407, the organic EL light emitting element is turned off in S408. In S411, the accumulated time when the organic EL light-emitting element is turned on and the accumulated time when the light is turned off are reset, and the sequence ends. Then, the process moves to the next frame and restarts from the start.

  Next, the operation timing when the wireless communication terminal is controlled based on the lighting control method of the organic EL light emitting element described in FIG. 6 will be described.

  FIG. 7 shows a lighting timing chart of the organic EL light emitting device of Example 2 and a transmission timing chart of the power amplifier (PA). In the range above the dotted line 201 (for example, the transmission power is 22 dBm or more), control is performed so that the organic EL light emitting element is turned off.

  FIG. 7 (a) shows a lighting timing chart of an organic EL light emitting element and a transmission timing chart of a power amplifier (PA) in the prior art. As shown in FIG. 7 (a), regarding the lighting on time T of the organic EL light emitting element and the lighting off time T ′ of the organic EL light emitting element, the time T + T ′ is constant, for example, 20 ms. ing. The timing at which the organic EL light emitting element is turned on and the timing at which the power amplifier (PA) is turned on are completely asynchronous. Furthermore, the power level when the transmission of the power amplifier (PA) is on is not constant, and when the organic EL light emitting element is turned on when the transmission power is large, the current flowing in the entire wireless communication terminal becomes a large current, A battery voltage drop will occur. Such a voltage drop of the battery voltage is related to the quality of the entire wireless communication terminal, and has an adverse effect such as excessive consumption of the battery accumulated charge and brightness fluctuation of the display panel.

FIG. 7B shows a lighting timing chart of the organic EL light emitting element and a transmission timing chart of the power amplifier (PA) in the second embodiment. At the timing when the organic EL light-emitting element is turned on, the transmission power of the RF signal (transmission power of Tc _{1 in} the figure) is equal to or less than a predetermined transmission power value (22 dBm in the figure). Keep the light on. The organic EL light emitting element is turned off during a period (Tc ₁ ′ in the figure) from when the predetermined transmission power value becomes 22 dBm or more to when the transmission power value becomes 22 dBm or less.

Here, the time during which the organic EL light emitting element is turned on is accumulated. Only when the transmission power value is a predetermined transmission power value of 22 dBm or less, the organic EL light emitting element is kept on until the integrated time for turning on the organic EL light emitting element reaches a predetermined value. In FIG. 7 (b), T + T ′, which is the sum of the organic EL light emitting element lighting on (T) and the organic EL light emitting element lighting off time (T ′), is controlled to be always constant. Therefore, the sum of the accumulated time to turn on the organic EL light emitting element (Tc ₁ + Tc ₂ + Tc ₃ ) and the accumulated time to turn off the organic EL light emitting element (Tc ₁ '+ Tc ₂ ' + Tc ₃ ') (Tc ₁ + Tc ₂ + Tc ₃ ) + (Tc 1 ′ + Tc ₂ ′ + Tc ₃ ′) is also controlled to be always constant, for example, 20 ms. Further, the ON / OFF duty ratio of the EL light emitting element is controlled in each frame so that T = Tc ₁ + Tc ₂ + Tc ₃ and T ′ = Tc ₁ ′ + Tc ₂ ′ + Tc ₃ ′ are satisfied.

Similarly, in FIG. 7 (b), the lighting-off time of the organic EL light-emitting element in the period of Td ₂ ′ is the integrated time for turning on the organic EL light-emitting element so that T + T ′ is constant. but next T, to lighting control based on a predetermined transmission power threshold as integrated time to turn off the organic EL light-emitting element is T ', turned on the organic EL light-emitting element in a period of Td _2.

  According to the configuration of the second embodiment, even when the backlight (or light emitting element) of the display device is turned on and the transmission power is transmitted on at the same time, while the transmission power value is large, the display device The lighting on of the backlight (or the light emitting element) and the transmission on of the transmission power do not occur at the same time. Therefore, no instantaneous large current flows, no voltage drop occurs in the circuit of the wireless communication terminal, and the battery lasts longer. Moreover, since only the lighting control and / or transmission power control is performed and the transmission timing of the RF signal is not changed, the communication standard can be observed. Also, the same brightness can be displayed on the same screen of the display device when the RF signal is transmitted and when it is not transmitted. According to the second embodiment, the communication system operates favorably in the case of a communication system that always transmits.

  Next, as Example 3, a lighting control method for an organic EL light-emitting element constituting a display panel of a wireless communication terminal according to the present invention will be described.

(Example 3)
FIG. 8 shows a flowchart for controlling lighting of the organic EL light-emitting element constituting the display panel of the wireless communication terminal according to the present invention. Since the same reference numerals described in FIG. 6 perform the same operation, the description of overlapping flows is omitted. The third embodiment is a modification of the second embodiment and uses not only lighting control but also transmission power control for the organic EL light emitting element.

  If the transmission power is equal to or lower than the predetermined value in S403, the organic EL light emitting element is turned off in S404. In S412, the time during which the organic EL light emitting element is turned off is integrated. In S413, it is determined whether the integrated time during which the organic EL light emitting element is turned off exceeds a predetermined value.

  If the predetermined value is not exceeded in S413, the process returns to S403. If the predetermined value is exceeded in S413, transmission is performed with the transmission power suppressed to a predetermined value or less in S414. In S415, the organic EL light emitting element is turned on, and in S416, the time during which the organic EL light emitting element is turned on is integrated.

  In S417, it is determined whether or not the accumulated time during which the organic EL light emitting element is turned on in one frame exceeds a predetermined value. If not, the process returns to S416 and the organic EL light emitting element is turned on. While waiting, wait until it exceeds a predetermined value. If the predetermined value is exceeded in S417, the accumulated time when the organic EL light emitting element is turned on and the accumulated time when the light is turned off are reset in S411, and the sequence ends. Then, the process moves to the next frame and restarts from the start.

  Next, the operation timing when the wireless communication terminal is controlled based on the lighting control method of the organic EL light emitting element described in FIG. 8 will be described.

  FIG. 9 (a) shows another transmission timing chart of the lighting control of the organic EL light emitting element and the power amplifier (PA) in the prior art. As shown in FIG. 9 (a), regarding the lighting on time T of the organic EL light emitting element and the lighting off time T ′ of the organic EL light emitting element, the time T + T ′ is constant, for example, 20 ms. ing. The timing at which the organic EL light emitting element is turned on and the timing at which the power amplifier (PA) is turned on are completely asynchronous. Furthermore, the power level when the transmission of the power amplifier (PA) is on is not constant, and when the organic EL light emitting element is turned on when the transmission power is large, the current flowing in the entire wireless communication terminal becomes a large current, A battery voltage drop will occur. Such a voltage drop of the battery voltage is related to the quality of the entire wireless communication terminal, and has an adverse effect such as excessive consumption of the battery accumulated charge and brightness fluctuation of the display panel.

FIG. 9B shows another transmission timing chart of the lighting control of the organic EL light emitting element and the power amplifier (PA) in the third embodiment. At the timing when the organic EL light-emitting element is turned on, the transmission power of the RF signal (transmission power of Tc _{1 in} the figure) is equal to or less than a predetermined transmission power value (22 dBm in the figure). The lighting on state is maintained (Te _{1 in the} figure). When the predetermined transmission power value becomes 22 dBm or more, the organic EL light-emitting element is turned off (Te ₁ ′ in the figure). Even if the transmission power exceeds the predetermined value as it is, if T ′ = Te ₁ ′, the organic EL light emitting element is turned on in order to make the lighting on / off duty ratio constant. Instead, the transmission power is suppressed to a predetermined transmission power value (22 dBm in the figure 201) (period Tf in the figure).

If the organic EL light emitting element is turned on and the requested transmission power from the base station is 22 dBm or less during the transmission power request period exceeding the predetermined value (that is, the period of Tf in the figure), the requested transmission is performed. Output transmit power according to power. It should be noted that the transmission power is always suppressed to a predetermined value of 22 dBm or less in the transmission power request period exceeding the predetermined value when the light emitting element is turned on (Te _{2 in the} drawing). However, when T = Te ₁ + Te ₂ , the light-on integrated lighting time and the light-off integrated time are reset, and this control is restarted from the beginning.

Also in this control, as in Example 2, T + T ′, which is the sum of the time for turning on the organic EL light emitting element (T) and the time for turning off the organic EL light emitting element (T ′) Is controlled to be always constant, and is the sum of the integrated time for turning on and off the organic EL light emitting element (Te ₁ + Te ₂ ) and the accumulated time for turning off the organic EL light emitting element (Te ₁ '). (Te ₁ + Te ₂ ) + Te ₁ ′ is also controlled to be always constant, for example, 20 ms. Further, the ON / OFF duty ratio of the EL light emitting element is controlled in each frame so that T = Te ₁ + Te ₂ and T ′ = Te ₁ ′ are satisfied.

  With respect to Examples 1 to 3, further effects of the present invention will be specifically described below.

  First, the problems of the prior art will be described in detail. When the organic EL light-emitting element is turned on, the power amplifier (PA) is turned on, or the current consumption of the wireless signal terminal increases, the voltage drop only occurs at that time due to the battery pack internal resistance or contact resistance. appear. Assume that the battery voltage before transmission of the RF signal is 3.5 V, and this radio signal terminal is shut down when the battery voltage becomes 3.4 V or less. It is conceivable that an organic EL light-emitting element panel instantaneously flows about 250 mA, and a power amplifier flows about 500 mA at maximum transmission. In this battery pack, the battery voltage drops by about 0.03V with a current increase of about 250mA.

  FIG. 10 shows how the battery voltage changes so as to contrast the prior art with Examples 1 to 3. FIG. 10 (a) is a diagram showing how the battery voltage changes in the prior art. In the relationship between the organic EL light emitting device and the power amplifier (PA), the voltage of the battery voltage is also applied when only the organic EL light emitting device is turned on or only the power amplifier (PA) is turned on. A descent occurs. However, since the battery voltage usually does not drop below 3.4V, the wireless signal terminal operates without any problem.

  However, in the prior art, the lighting-on of the organic EL light-emitting element and the transmission-on of the power amplifier (PA) may occur simultaneously. In such a case, if the battery voltage drops below a predetermined threshold value of 3.4 V, the wireless signal terminal is shut down and cannot be used any more. In FIG. 10 (a), if the organic EL light emitting element is set to 3.47V before turning on (202 in the figure), the battery voltage becomes 3.44V by turning on the organic EL light emitting element (shown in 203). ). When the power amplifier (PA) is turned on in this state, the battery voltage becomes 3.38V (204 in the figure), becomes a threshold value of 3.4V or less, and the wireless signal terminal is shut down.

  FIG. 10 (b) is a diagram showing how the battery voltage changes in Examples 1 to 3. Even if the power amplifier (PA) starts transmitting the RF signal at the same timing as in FIG. 10 (a), the battery voltage does not fall below 3.4V and can continue to be used as it is. In FIG. 10 (b), when the organic EL light emitting element is turned on at 3.47V before turning on (205 in the figure), when the organic EL light emitting element is turned on, the battery voltage becomes 3.44V (shown at 206). When the power amplifier (PA) is turned on in this state, the battery voltage becomes 3.41 V (207 in the figure) and is equal to or higher than the threshold value of 3.4 V, so that the use of the radio signal terminal can be continued without shutting down the radio signal terminal.

  Furthermore, even when a battery having the same battery capacity is used, according to the first to third embodiments, the wireless signal terminal can be used for a long time by one charge, and the wireless signal terminal using the battery is used. Is particularly effective. For example, it is assumed that the battery voltage drop from 3.5V to 3.4V takes 60 minutes due to the use of a radio signal terminal (voltage drop of 0.00167V / min). In the case of FIG. 10, if the wireless signal terminal can be used until the battery voltage 3.5V reaches 3.46V, it can be used for 20 minutes longer than the conventional technology. That is, a wireless communication terminal having a continuous call time of 200 minutes can be used for 220 minutes.

  The lighting control or the transmission power control in the first to third embodiments may be always controlled, and may be operated only when the battery voltage becomes a certain threshold value or less. By always operating, the peak current of the wireless signal terminal can be lowered, and by reducing the peak current supplied from the battery, the battery life can be extended.

  Further, the lighting control or transmission control of the first and second embodiments can be operated only when the battery voltage becomes a certain threshold value or less. In this case, the lighting of the organic EL light emitting element is turned on and the transmission of the power amplifier (PA) is turned on at the same time, and the probability of using the control of the third embodiment that must reduce the transmission power can be reduced.

  In the lighting control or transmission power control of the first to third embodiments, the unit for controlling on / off (the value of T + T ′ in the figure) is, for example, kept constant at 20 ms, and the duty ratio within the certain period is constant. By doing so, the brightness on the screen can be made constant. This is because the blinking cannot be detected by human vision, and the integrated power value in one frame is constant, and there is no change in brightness depending on whether transmission is performed or not. The above problem does not occur.

  Since the transmission timing is not changed in the lighting control or the transmission power control in the first to third embodiments, the communication standard can be observed. Further, the control method of suppressing the maximum transmission power depending only on the battery voltage is actually used, and reducing the transmission power by about 1 dBm in a region where the transmission power is large does not cause a substantial problem. In a region where the transmission power is large, a difference occurs in the current consumed by several tens of mA due to a difference in the transmission power of 1 dBm. Therefore, if the lighting control or the transmission power control in Examples 1 to 3 is used, the consumption current is reduced. The effect is extremely large.

  Next, as Example 4, a lighting control method for an organic EL light-emitting element constituting a display panel of a wireless communication terminal according to the present invention will be described.

(Example 4)
FIG. 11 shows a flowchart for controlling lighting of the organic EL light-emitting element constituting the display panel of the wireless communication terminal according to the present invention. Assume that the wireless signal terminal starts transmitting an RF signal in S701. In S702, it is determined whether or not it is the timing when the organic EL light-emitting element is turned on. The method for determining whether or not it is the timing to turn on the lighting is based only on whether or not it is the lighting on timing for turning on the light at a predetermined cycle. If it is time to turn on in S702, it is determined in S703 whether or not the transmission power request from the base station is a predetermined value (for example, 22 dBm) or more.

  In S703, if an RF signal is transmitted with a transmission power equal to or higher than a predetermined value, the main display part of the display screen (for example, an application part such as a videophone) is turned off and the display screen is turned off in S704. The sub display section (for example, an icon display section such as a remaining battery level or a clock display) is turned on. If the RF signal is transmitted with a transmission power less than the predetermined value in S703, the main display unit and the sub display unit of the organic display screen are turned on in S705.

  In S706, the time when the main display portion is turned on and the time when the sub display portion is turned on are respectively integrated. In S707, it is determined whether or not the accumulated time during which the main display is turned on in one frame exceeds a predetermined value. If not, the process returns to S703. If the predetermined value is exceeded in S707, the main display unit and the sub display unit are turned off in S708. Then, in S709, the time when the main display unit is turned off is integrated, and in S710, it is determined whether the integrated time when the main display unit is turned off in one frame exceeds a predetermined value.

  In S710, if the accumulated time during which the main display unit is turned on does not exceed the predetermined value, the process returns to S709 and waits until the accumulated time during which the main display unit is turned on exceeds the predetermined value. In S710, if the accumulated time during which the main display is turned on exceeds a predetermined value, the accumulated time during which the main display is turned on and the accumulated time during which the main display is turned off in S711. Then, all the accumulated time when the sub display unit is turned on and the accumulated time when the sub display unit is turned off are reset, and the sequence is terminated. Then, the process moves to the next frame and restarts from the start.

  If an RF signal is transmitted with a transmission power of a predetermined value or more in S703, the main display unit is turned off and the sub display unit is turned on in S704. In S712, the times when the main display unit is turned off and the sub display unit are turned on are integrated.

  In S713, it is determined whether or not the accumulated time when the main display unit is lit off exceeds a predetermined value. If it has exceeded, the process proceeds to S714, where the main display unit is lit on and the sub display unit is lit off. To do.

  In S715, the time during which the main display is turned on is accumulated, and in S716, the main display is turned on, and it is determined whether the accumulated time has exceeded a predetermined value. If the predetermined value is exceeded in S716, the accumulated time in which the main display unit is turned on, the accumulated time in which the main display unit is lit off, the accumulated time in which the sub display unit is lit on, and the sub time in S711. All the accumulated time when the display unit is turned off is reset, and the sequence ends. Then, the next frame shifts and restarts from the start.

  If the predetermined value is not exceeded in S716, the process returns to S715 and waits until the predetermined value is exceeded. If it is determined in S713 that the predetermined value has not been exceeded, it is determined in S717 whether or not the accumulated time during which the sub display unit is turned on exceeds a predetermined value. If the predetermined value is exceeded in S717, the main display unit is turned off and the sub display unit is turned off in S718, and the process returns to S713. If the predetermined value is not exceeded in S717, the main display unit is turned on, the sub display unit is turned off in S713, and the process returns to S713.

  In this way, the display screen is controlled to be lit separately, for example, in a main display section that captures the face of the other party on a videophone and a sub display section that displays an icon such as a remaining battery display or a clock display, When transmitting at a transmission power higher than the value, control is performed so that the main / sub display unit is not turned on at the same time, and the on / off duty ratio of the main display unit is always maintained constant. As a result, it is possible to prevent a change in brightness at a portion where the user is mainly gazing. Further, the peak current of the wireless communication terminal can be reduced by not turning on the main / sub display unit at the same time.

  In addition, by controlling specific light emitting elements on the display screen, the main display unit is turned on / off at a normal duty ratio, and the main display unit such as a soft menu key is turned on / off according to the transmission power. It can also be controlled. As a result, it is possible to prevent a change in brightness at a portion where the user is mainly gazing.

  Further, the lighting on / off control can be performed in accordance with the transmission power so that the main display unit is turned off and the sub display unit is turned on depending on the remaining battery level. Thereby, only the part which a user should mainly watch can also be lighted.

  In the above-described embodiment, the ON time is measured until the total lighting ON period of the organic EL light emitting element reaches T, and the lighting is turned OFF when T is reached. During the on-period of the light-emitting element based on the off cycle, the time when the light-emitting element is turned off is counted according to the transmission power being turned on, and the light-emitting element is turned on during the light-emitting element off period for the measured time. The total light emission time may be a constant value (T).

  Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many changes and substitutions can be made within the spirit and scope of the invention. For example, in the embodiment, a wireless communication terminal provided with a display device using an organic EL light emitting element has been described, but other display devices such as a liquid crystal panel liquid crystal display device (LCD), a plasma display device (PDP), The present invention can also be applied to field emission display devices (FED) and inorganic electroluminescence (EL). In the embodiment, the control over time has been described according to the flowchart, but the same effect as that described in the embodiment can be achieved by causing the display unit to display the data accumulated in the frame buffer in a delayed manner. Accordingly, the invention should not be construed as limited by the embodiments described above, but only by the claims.

  Since the lighting on / off control of the backlight (or light emitting element) of the display device is controlled in association with the transmission on of the RF signal that is an excessive transmission power, the brightness of the display unit becomes more stable and the battery lasts longer. Since excellent usability can be exhibited, it is useful for a wireless communication terminal including a display device.

It is a block diagram of the radio | wireless communication terminal by this invention. It is a control block diagram of a display panel provided with a plurality of light emitting elements configured by a matrix of column rows. It is a figure which shows an example in the case of column row address designation | designated of a display part provided with the several light emitting element comprised by the column row matrix. It is a flowchart figure which controls lighting of the organic electroluminescent light emitting element which comprises the display panel of the radio | wireless communication terminal by this invention. FIG. 5 (a) is a timing chart of the prior art, and FIG. 5 (b) is a timing chart of the first embodiment. It is a flowchart figure which controls lighting of the organic electroluminescent light emitting element which comprises the display panel of the radio | wireless communication terminal by this invention. FIG. 7 (a) is a lighting timing chart of the organic EL light emitting element and the transmission timing of the power amplifier (PA) in the prior art, and FIG. 7 (b) is a lighting of the organic EL light emitting element in Example 2. It is a transmission timing chart figure of control and a power amplifier (PA). It is a flowchart figure which controls lighting of the organic electroluminescent light emitting element which comprises the display panel of the radio | wireless communication terminal by this invention. FIG. 9 (a) is an organic EL light emitting element lighting control and another transmission timing chart of the power amplifier (PA) in the prior art, and FIG. 9 (b) is an organic EL light emitting element in Example 3. It is another transmission timing chart figure of lighting control and power amplifier (PA). FIG. 10 (a) is a diagram showing how the battery voltage changes in the prior art, and FIG. 10 (b) is a diagram showing how the battery voltage changes in Examples 1 to 3. It is a flowchart figure which controls lighting of the organic electroluminescent light emitting element which comprises the display panel of the radio | wireless communication terminal by this invention.

Explanation of symbols

101 CPU
102 RF block
103 Display control unit
104 Display panel
105 Power supply
106 battery
107 frame buffer
108 Brightness control unit
109 Display
402 Display panel controller
403 display
404 Column electrode signal driver
405 Row electrode signal driver

Claims (7)

In a radio signal terminal comprising a display means having a light emitting means and a transmission circuit having a power amplifier that turns transmission on / off according to the transmission timing,
Brightness control means for controlling on / off of the light emitting means at a cycle according to the required brightness of the display means;
Power control means for turning off the light emitting means in response to the transmission on of the power amplifier during the on period of the light emitting means under the control of the luminance control means;
A time measuring means for measuring a time when the light emitting means is turned off by the power control means,
The brightness control means includes
A wireless communication terminal that turns on the light emitting means for a time counted by the time measuring means during a period when the light emitting means is off and the power amplifier is off transmission. In a radio signal terminal comprising a display means having a light emitting means and a transmission circuit having a power amplifier that turns transmission on / off according to the transmission timing,
Brightness control means for turning on / off the light emitting means at a cycle according to the required brightness of the display means;
Power control means for turning off the light emission means when the transmission power of the transmission circuit exceeds a predetermined value during the ON period of the light emission means under the control of the brightness control means;
A time measuring means for measuring a time when the light emitting means is turned off by the power control means,
The brightness control means includes
A wireless communication terminal that turns on the light emitting means for a time counted by the time measuring means during a period when the light emitting means is off and the power amplifier is off transmission. The light emitting means includes a plurality of light emitting elements,
The power control means includes
Turning off some of the light emitting elements;
The brightness control means includes
3. The radio communication terminal according to claim 1, wherein, during a period in which the light emitting unit is off and the power amplifier is in a transmission off state, the part of the light emitting elements is turned on for a time measured by the time measuring unit. The power control means includes
3. The wireless communication terminal according to claim 2 , wherein when the time measured by the time measuring unit exceeds a predetermined time, the transmission power of the transmission circuit is suppressed to the predetermined value or less. In a power control method for a wireless communication terminal comprising: a display unit having a light emitting unit that is turned on / off in a cycle according to a required luminance; and a transmission unit that is turned on / off according to a transmission timing.
Turning off the light emission means when the transmission means is on during the ON period of the light emission means based on the period;
Integrating the time during which the light emitting means is turned off in the on period of the light emitting means based on the cycle;
A power control method for a wireless communication terminal, comprising: turning on the light emitting means for the integrated time when the transmission means is in transmission off during the off period of the light emitting means based on the cycle. In a power control method for a wireless communication terminal comprising: a display unit having a light emitting unit that is turned on / off in a cycle according to a required luminance; and a transmission unit that is turned on / off according to a transmission timing.
Turning off the light emitting means when the transmission power of the transmitting means exceeds a predetermined value during the ON period of the light emitting means based on the cycle;
Integrating the time during which the light emitting means is turned off in the on period of the light emitting means based on the cycle;
A power control method for a wireless communication terminal, comprising: turning on the light emitting means for the integrated time when the transmission means is in transmission off during the off period of the light emitting means based on the cycle.   7. The power control method for a radio communication terminal according to claim 6, further comprising a step of suppressing the transmission power to be equal to or less than the predetermined value when the accumulated time exceeds a predetermined time.

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