JP2003258975A - Mobile apparatus, illumination driving ic, and adjusting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To save battery power consumption by luminance adjustment using an photosensor and to easily adjust the output level of the photosensor. <P>SOLUTION: The mobile apparatus which is equipped with a display part 3, a light emission part 6 illuminating it, a driving part 13 which generates its driving electric power from the output of a battery 5, a luminance adjustment part 12 varying the driving electric power, and the photosensor detecting circumferential lightness and performs variation control over the luminance adjustment part 12 according to the output of the photosensor 2 is provided with a level adjusting means 11 which adjusts the output level of the photosensor 2 and a control arithmetic means 8 which selectively performs a process for calculating its adjustment value according to the output of the photosensor 2. When the photosensor output level is adjusted, the control arithmetic means 8 performs the luminance value calculating process while the mobile equipment is placed in environment of prescribed illuminance. During the adjustment, the value of a bias resistance 11a is varied and the gain of an amplifier 11b for output is also varied. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable device which detects ambient illuminance and automatically adjusts the brightness of a display section, and more particularly to a technique for adjusting an output level of an optical sensor for detecting illuminance. The present invention also relates to a light emission drive IC suitable for incorporation in such a mobile device and an adjustment method for performing level adjustment.

[0002] A portable device is generally operated by being supplied with power from a battery at all times or at least temporarily by switching or the like. Typical examples thereof are a portable telephone device and a personal digital assistant (PDA). ), A portable audio player, a portable video player, a portable disc player, and the like. Mobile phone devices include PHS (Pers
onal Handyphone System) is also applicable. In addition to the above portable playback device, a portable recorder such as a recording device or a recording / playback device also corresponds to a mobile device.

[0003]

2. Description of the Related Art There are known some portable devices equipped with an optical sensor for detecting the ambient brightness and adapted to adjust the brightness of a backlight of a liquid crystal panel on the basis of the output thereof (Japanese Patent Laid-Open No. Hei 9-9). 185036, JP-A-11-316
364 and JP-A-10-148807). A phototransistor or the like is used for the optical sensor,
The output level has "variation" due to the nonuniformity of the h _fe characteristics of the individual transistors. Therefore, for optical sensors, before shipment or before incorporating them into mobile devices, it is also possible to select and extract objects with the same characteristics, or to adjust the characteristics by laser trimming, focused ion beam repair, etc. ing.

[0004]

However, such sorting work and characteristic improvement work are troublesome, work efficiency is not good, and the defective product rate tends to be high. For this reason, the cost of the optical sensor does not decrease, and it is difficult to incorporate the optical sensor into mobile devices with severe price restrictions. For example, we would like to save power consumption by incorporating an optical sensor and brightness adjustment means into a portable device such as a mobile phone that requires a long operating time with a single charge. When the level variation is large, power is often wasted, but on the other hand, it is unacceptable to perform the selection work or the like to make the characteristics of the photosensors uniform, because this increases the cost.

Therefore, by utilizing the fact that the optical sensor is attached so as to be able to detect the ambient illuminance when it is incorporated in the portable device, the optical sensor itself does not need to have its characteristics matched in advance. The challenge is to make technical efforts so that the sensor output level can be easily adjusted. The present invention has been made to solve such problems, and realizes a portable device that not only saves battery power by adjusting the brightness using an optical sensor but also can easily adjust the output level of the optical sensor. The purpose is to
It is also an object to realize a light emission drive IC suitable for incorporation in such a portable device. Another object of the invention is to realize an adjusting method for easily adjusting the level of such a portable device.

[0006]

With respect to the first to fifth solving means invented to solve the above problems,
The configuration and action and effect will be described below.

[First Solving Means] A portable device according to the first solving means is a display unit as described in claim 1 at the time of filing the application.
A light emitting unit that performs the illumination, a drive unit that generates the drive power from a battery output, a brightness adjustment unit that changes the drive power, and an optical sensor that detects ambient brightness are provided. In a portable device that performs variable control based on the output of the optical sensor, a level adjusting unit that can adjust the output level of the optical sensor and a process of calculating the adjustment value based on the output of the optical sensor are selectively used. And a control calculation means for performing the above.

Further, the light emission drive IC of the first solution suitable for being incorporated in the electronic circuit section is, as described in claim 6 at the beginning of the application, a terminal for receiving a battery output and a light emission section. A terminal for transmitting driving power, a driving unit for generating the driving power from the battery output, a brightness adjusting unit for varying the driving power, a terminal for receiving the output of the optical sensor, and the output of the optical sensor. It is a combination of level adjusting means for adjusting the level. Such a light emission driving IC is incorporated in a battery-powered portable device, and a control calculation means for selectively calculating the adjustment value of the level adjustment means based on the output of the optical sensor is also provided.
By variably controlling the brightness adjustment of the illumination of the display unit according to the ambient brightness, the portable device of the above first solving means can be easily completed. Light emission drive I of each solution described below.
The same applies to C.

Further, the adjusting method of the first solving means performed for such a portable device is, as described in claim 11 at the beginning of the application, the optical sensor output level of the portable device of the first solving means. The display unit is provided with control calculation means for performing adjustment or incorporating the light emission drive IC of the first solution means and selectively performing the process of calculating the adjustment value of the level adjustment means based on the output of the optical sensor. When adjusting the optical sensor output level of a battery-powered portable device that variably controls the brightness adjustment of the illumination according to the ambient brightness, place the portable device in an environment of a predetermined illuminance and use the control calculation means. The adjustment value calculation process is executed. Note that the same adjustment can be performed for the adjustment of the optical sensor output level of the mobile device of each of the solving means described below.

Here, the "optical sensor output level" and the "optical sensor output level" mean the level of the signal output from the optical sensor according to the input light quantity, and the "level adjustment" is This is performed so that a signal having a predetermined value is output when a predetermined amount of light is input.

In the portable device or the like of the first solving means as described above, the ambient brightness is detected by the optical sensor,
Variable control of the brightness adjustment unit is performed based on the output,
Since the drive power supplied from the drive unit to the light emitting unit is variably controlled, the brightness of the display unit is adjusted according to the ambient brightness, so if the output level of the optical sensor is appropriate, the visibility is impaired. It is possible to reduce wasteful consumption of battery power without needing to do so. Further, the output level of the optical sensor can be adjusted using the level adjusting means even after the optical sensor is incorporated in the portable device.

When the adjustment is performed, the portable device is placed under the environment of the default illuminance using a jig or the like that can keep the ambient brightness of the portable device at a predetermined illuminance, and the adjustment by the control calculation means is performed. The value calculation process is executed.
Then, an appropriate adjustment value is calculated by the processing.
By performing the level adjustment with this value, the output level of the optical sensor of the mobile device is adjusted to an appropriate state, so that the appropriate level adjustment can be easily performed. After such adjustment, the output level of the optical sensor is appropriately maintained based on the adjusted value, so that a portable device as if an optical sensor having optimal characteristics is extracted and incorporated can be completed.

Accordingly, if the characteristics of the optical sensor alone are preliminarily aligned, it is of course possible to easily adjust the optical sensor output level of the portable device to an appropriate state without performing such a thing. . In addition, after the adjustment, the brightness adjustment using the optical sensor is appropriately performed without any variation in any mobile device, and useless power consumption is suppressed. Therefore, according to the present invention, not only the battery power is saved by the brightness adjustment using the photosensor, but also the photosensor output level can be easily adjusted.

[Second Solving Means] The portable device of the second solving means is, as described in claim 2 at the beginning of the application, the above-mentioned first means.
The portable device according to the first aspect, wherein when the variable control of the brightness adjusting unit is performed based on the output of the optical sensor, the driving power is first increased with respect to the increase of the output of the optical sensor, The control of the first characteristic, which starts to decrease, is performed.

The light emitting drive IC of the second solving means is
As described in claim 7 at the beginning of the application, in the light emission drive IC of the first solving means, when the variable control of the brightness adjusting unit is performed based on the output of the optical sensor, the output of the optical sensor is changed. It also has a built-in means for controlling the first characteristic in which the driving power is first increased with respect to the increase and then starts to decrease from the middle.

In the portable device or the like of the second solving means, the brightness is low when the surroundings are dark and bright, and the brightness is highest when the surroundings are in the middle. This allows
Thus, the reflection type display unit, which uses the reflected light as the main light source and compensates the shortage by the illumination of the light emitting unit, can be sufficiently illuminated without waste. Therefore, according to the present invention, even if the display unit is of a reflective type, not only the battery power is saved by the brightness adjustment using the optical sensor, but also the optical sensor output level can be easily adjusted.

[Third Solving Means] The portable device of the third solving means is, as described in claim 3 at the beginning of the application, the above-mentioned second means.
In the portable device according to the first aspect of the present invention, the control of the first characteristic and the control of the second characteristic that the driving power is initially increased and made constant during the increase of the output of the optical sensor are selected. It is designed to be carried out in a targeted manner.
Further, the light emission drive IC of the third solution means is the light emission drive IC of the second solution means as described in claim 8 at the beginning of the application, wherein the control of the first characteristic and the optical sensor are performed. With respect to the increase in the output, the control of the second characteristic that the driving power is first increased and then made constant from the middle is selectively performed.

In the portable device or the like of the third solving means as described above, when the control of the first characteristic is selected, as described above, the reflection type display section is sufficiently lighted without waste. On the other hand, when the control of the second characteristic is selected, the brightness is adjusted so as to match the brightness of the surroundings when the surroundings are dark, and the brightness hardly changes when the surroundings are sufficiently bright. In the latter case, the semi-transmissive display unit, which uses the reflected light as the light source and the illumination of the light emitting unit together in a master / slave state, is sufficiently illuminated without waste.

As a result, when the reflective display unit or the semi-transmissive display unit is targeted, sufficient illumination is achieved without waste, which facilitates the design of the device. At the same time, the range of application and application of ICs will expand. Therefore, according to the present invention, the battery power can be saved and the output level of the optical sensor can be easily adjusted by adjusting the brightness using the optical sensor regardless of whether the display unit is a reflective type or a semi-transmissive type.

[Fourth Solving Means] The portable equipment of the fourth solving means is the portable equipment of the above-mentioned second and third solving means, as described in claim 4 at the time of filing the application. The control of the third characteristic for monotonically increasing the drive power with respect to the increase in the output of the sensor is also selectively performed. In addition, the light emission drive IC of the fourth solution means
Is a light emission drive IC of the said 2nd, 3rd solution means as described in Claim 9 at the time of application original, Comprising: The said drive electric power increases monotonically with respect to the increase of the output of the said optical sensor. The control of the three characteristics is also selectively performed.

In the portable device or the like of the fourth solving means as described above, when the control of the first characteristic is selected, as described above, the reflection type display section is fully illuminated without waste, When the control of the second characteristic is selected, the semi-transmissive display unit is illuminated without waste as described above, while when the control of the third characteristic is selected, the adjustable range of Luminance is adjusted so as not to lose the surrounding brightness. In the latter case, the transmissive display unit whose main light source is the illumination of the light emitting unit is appropriately illuminated without overcoming the ambient brightness and without wasting power.

As a result, whether the reflective display unit, the semi-transmissive display unit or the transmissive display unit is targeted, the illumination can be performed sufficiently without waste. Therefore, almost all non-self-luminous display parts that do not emit light are suitable. Therefore,
According to the present invention, whether the display unit is of a reflective type, a semi-transmissive type, or a transmissive type, not only saves battery power by adjusting the brightness using an optical sensor, but also can easily adjust the output level of the optical sensor.

[Fifth Solving Means] The portable device of the fifth solving means is, as described in claim 5 at the time of filing of the application, the first device described above.
In the portable device according to the fourth solution means, the optical sensor is a phototransistor, and the level adjusting means variably controls the value of the bias resistance of the transistor when adjusting the output level of the optical sensor. At the same time, the gain of the output amplifier is variably controlled.

The light emission drive IC of the fifth solution means
As described in claim 10 at the beginning of the application, the above-mentioned first to fourth
And a resistance element or a resistance circuit that serves as a bias resistance when a phototransistor is used as the optical sensor,
An output amplifier that amplifies the output of the photosensor, and variably controls the resistance value of the resistance element or the resistance circuit when adjusting the output level of the photosensor and also variably controls the gain of the amplifier. It is like that.

Further, the adjusting method of the fifth solving means performed for such a portable device is, as described in claim 12 at the beginning of the application, the optical sensor output level of the portable device of the fifth solving means. The display unit is provided with control calculation means for performing adjustment, or incorporating the light emission drive IC of the fifth solution means and selectively performing a process of calculating the adjustment value of the level adjustment means based on the output of the optical sensor. When adjusting the optical sensor output level of a battery-powered portable device that variably controls the brightness adjustment of the illumination according to the ambient brightness, place the portable device in an environment where the illuminance changes within a predetermined range, and The adjustment value calculation process by the control calculation means is executed.

In the portable device or the like of the fifth solving means as described above, level adjustment is performed by setting two values of bias and gain. Therefore, if there is one variable, there are two values of intercept and inclination. The output level of the optical sensor can be grasped by the linear function determined by, and an appropriate adjustment value can be obtained by performing the conversion operation from the linear function to the linear function, so the level can be adjusted easily and surely. .

When the adjustment is performed, the adjustment value calculation process is executed in an environment where the ambient brightness of the portable device changes, so that it is necessary to grasp the characteristics of the optical sensor output level. Since data is obtained for a plurality of points, a straight line function can be obtained by a simple calculation by using the data of two points. If the estimation calculation such as the regression analysis or the least squares method is performed using the data of three or more points, the linear function having the higher degree of conformity and the degree of approximation can be obtained. As a result, the optical sensor output level is in an appropriate state without variation over the entire range in which the output value of the optical sensor changes. Therefore, according to the present invention, not only the battery power is saved by the brightness adjustment using the optical sensor, but also the wide range adjustment of the optical sensor output level can be easily performed.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION With regard to the portable device, the light emission drive IC, and the adjusting method of the present invention achieved by the above-described solution means, concrete modes for carrying out the same will be described in the following first to sixth embodiments. An example will be described. The first embodiment shown in FIGS. 1 to 3 embodies the above-mentioned first and fifth solving means (initial claims 1, 5, 6, 10, 11, 12). The second embodiment shown in is a modification thereof.
Further, the third embodiment shown in FIG. 5 embodies the above-mentioned second solving means (initial claims 2 and 7), and the fourth embodiment shown in FIG. The third solving means (initial claims 3 and 8) is embodied, and the fifth embodiment shown in FIG. 7 is the fourth solving means (initial claim 4) described above. is there. The sixth embodiment shown in FIG. 8 also embodies the fourth solving means (initial claim 9).

[0029]

The first embodiment of the portable device and the light emission drive IC of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a structure of a mobile phone 1 as a specific example of a mobile device, in which (a) is an external perspective view,
(B) is a side view, (c) is a block diagram of an electronic circuit,
(D) is a circuit diagram of a main part.

This mobile phone 1 has a front panel (see FIG. 1A), in addition to a microphone and a speaker required for a call, an optical sensor 2 including a phototransistor and a color including a liquid crystal panel. Alternatively, a monochrome display unit 3, a key 4 used not only for dial operation but also for switching operation modes, and the like are provided. The optical sensor 2 is arranged as close to the display unit 3 as possible, and is attached with the light receiving unit facing outward so as to detect the ambient brightness.

Further (see FIG. 1B), a rechargeable battery 5 is detachably or fixedly mounted on the back surface of the mobile phone 1 and the like, and the light emitting part 6 is provided inside the mobile phone 1.
Is built in. The light emitting section 6 is composed of one or a plurality of light emitting diodes (LEDs) and electroluminescence (EL) elements, and is arranged on the back side of the display section 3 when used as a backlight and when used as a front light. Are arranged beside the display unit 3 or the like.
In any case, when the driving power is supplied to emit light, the display unit 3 is directly or indirectly illuminated.

Further (see FIG. 1C), the mobile phone 1
The electronic circuit is stored in the inside of it, and it is equipped with a general-purpose microprocessor 8 (CPU) that performs various operations in addition to control of communication and telephone calls.
A light emission drive IC 10 that drives the light emitting unit 6 is also incorporated. The microprocessor 8 is composed of a non-volatile memory such as a ROM or a flash memory, or a memory 7 including a part thereof, or an A for fetching the output of the optical sensor 2.
The / D conversion circuit 9 or the like is attached or incorporated. In a normal mode such as a call mode or a standby mode, the output of the optical sensor 2 is fetched via the light emission drive IC 10 and the A / D conversion circuit 9, and the illumination brightness of the display unit 3 is adjusted based on the captured output. There is. Therefore, the light emission intensity of the light emitting unit 6 is variably controlled by sending a command to the light emission driving IC 10 to control the variable state of the brightness adjusting unit 12 therein.

When the level adjustment mode is selected by a specific operation of the key 4 or a control signal via a connector (not shown), the microprocessor 8 switches the operation mode from the normal mode to the level adjustment mode, It functions as a control calculation means, performs processing as described in detail later in the operation description, and calculates the adjustment value of the level adjustment means 11 based on the output of the optical sensor 2. The adjustment value is stored and held in the memory 7, and is sent to the light emission drive IC 10 when initialization is required such as when the power is turned on, and the adjustment state of the level adjusting means 11 therein is brought into a state corresponding to the adjustment value. Is also becoming.

The light emission drive IC 10 (see FIG. 1 (c),
(D)) This is a one-chip IC, on which the circuits of the level adjusting means 11, the brightness adjusting section 12, and the driving section 13 are mounted, and in addition to receiving the output of the battery 5, the driving section 13
To send to the light emitting unit 6, the terminal for sending the driving power generated by the driving unit 13 and adjusted by the brightness adjusting unit 12 to the light emitting unit 6, and for sending the raw output from the optical sensor 2 to the level adjusting unit 11. Terminal, and the optical sensor output whose level is adjusted by the level adjusting means 11 is A / D conversion circuit 9
Necessary terminals such as a terminal for sending out to, a terminal for receiving an instruction value sent from the microprocessor 8 and the like are provided. The serial-parallel converter 14 is also integrated in one chip so that various commands can be received from the microprocessor 8 with a small number of terminals.

The serial-parallel conversion unit 14 is provided with a shift register or the like, and converts the adjustment value or the adjustment value sent from the microprocessor 8 in bit serial into a parallel digital value, and these instruction values are converted. The adjustment value is held until the next update, and the adjustment value is sent to the brightness adjusting section 12 and the adjustment value is sent to the level adjusting means 11.
The drive unit 13 generates the drive power of the light emitting unit 6 from the battery output, and in order to avoid / suppress the drive power from varying depending on the charging / discharging state of the battery 5, a booster circuit with a voltage stabilizing circuit is provided. Etc.

The brightness adjusting section 12 is provided with a PWM circuit 12a which is inserted in a power supply line from the driving section 13 to the light emitting section 6 so as to be able to cut off conduction, and drives the light emitting section 6 by a pulse width modulation method. It changes the electric power. The variable control is performed according to the adjustment value sent from the microprocessor 8 via the serial-parallel converter 14, and the duty ratio of the driving power corresponds to the adjustment value. Therefore, when the adjustment value is updated by the microprocessor 8, the drive power of the light emitting unit 6 is adjusted at any time following the update.

The level adjusting means 11 comprises a bias resistor 11a of the photosensor 2 which is a phototransistor, and an output amplifier 11b which amplifies the voltage generated in the photosensor 2, that is, the raw output of the photosensor 2 as an analog signal. However, the output of the amplifier 11b is sent to the A / D conversion circuit 9 as the level-adjusted photosensor output voltage Vo. In order to make the output level of the optical sensor 2 adjustable, for example, a variable resistance element is adopted for the bias resistor 11a, a gain variable amplifier is adopted for the output amplifier 11b, and both are serial-parallel connected from the microprocessor 8. It is variably controlled according to the adjustment value sent through the conversion unit 14. Regarding the bias resistor 11a, by using a logarithmic compressor for light amount conversion, the output level can be converted into a straight line with respect to the light intensity (gamma correction).

The portable device and the light emission drive I of the first embodiment
With respect to C, the usage mode and operation will be described, including the method of adjusting the optical sensor output level. FIG. 2 is a diagram for explaining the adjustment work, and FIG. 3 is a graph showing how the output level of the optical sensor varies.
(B) is after adjustment.

A level adjusting process is added to any process after the assembly is completed and before the shipment, such as the final stage of the manufacturing process of the mobile phone 1 and the subsequent inspection process.
The output level of the optical sensor 2 is adjusted. Specifically (see FIG. 2), the mobile phone 1 assembled to an operable position is moved to the adjustment jig 20, and the mobile phone 1 is covered with a cover 21 to block ambient light and the light 22 is turned on. The mobile phone 1 is turned on to set the ambient brightness to a known illuminance Lx. In that state, the operation mode of the mobile phone 1 is set to the level adjustment mode by remote control or the like. Then, the illuminance Lx is gradually increased by a predetermined amount at predetermined time intervals. Or, decrease from the highest illuminance to the lowest illuminance.

Then, in the electronic circuit of the mobile phone 1 placed in an environment in which the illuminance changes in such a predetermined range, first, the adjustment value of the level adjusting means 11, that is, the resistance value of the bias resistor 11a and the gain of the amplifier 11b. Are initialized to a predetermined value such as the central value of the adjustment range, and thereafter, the adjustment value calculation process is executed by the microprocessor 8 as the control calculation means in parallel with the change of the illuminance Lx.

Specifically, the output voltage Vo of the optical sensor 2 is repeated at the same time interval as the time interval at which the illuminance Lx changes.
Are sampled and taken into the microprocessor 8. Then, the horizontal axis is the illuminance Lx and the vertical axis is the output voltage V
A straight line that best approximates the plurality of sampling points described above is obtained by a least squares calculation or the like in the two-dimensional space in which o is taken. Then, the optimum resistance value of the bias resistor 11a is calculated based on the intercept value, the optimum gain of the amplifier 11b is calculated based on the inclination, and these adjustment values are sent to the level adjusting means 11, Level adjustment is completed.

In this way, if the simple operation of setting the mobile phone 1 on the adjusting jig 20 is carried out, then automatically, or by additionally installing the adjusting jig 20 and a transfer robot or the like suitable for it on the production line. The output level of the optical sensor 2 is automatically and easily adjusted. Even if there is "variation" in the output level immediately after initialization due to the "variation" of the individual optical sensors 2 (see FIG. 3A), the "variation" is found in the adjusted output level. Is almost eliminated (see FIG. 3 (b)).

The mobile phone 1 which has been adjusted as described above is shipped and used for a call or communication in the normal mode.
At that time, the brightness around the mobile phone 1 is detected by the optical sensor 2, and the output voltage Vo thereof is adjusted by the level adjusting means 11.
Is adjusted so that it does not vary, and then is taken into the microprocessor 8. Then, based on that, the microprocessor 8 calculates the brightness of the display unit 3 that is adapted to the ambient brightness without waste, and the adjustment value corresponding to the brightness is calculated.
Is sent to the brightness adjusting unit 12.

In this way, also in this mobile phone 1, the light emission intensity of the light emitting unit 6 and thus the brightness of the display unit 3 can be appropriately changed according to the ambient brightness, thereby illuminating the display unit 3 without impairing the visibility. You can save the power you spend. Moreover, in the mobile phone 1, it is possible to omit the operations such as selection and extraction of the optical sensor 2, laser trimming, and focused ion beam repair.

[0045]

Second Embodiment The portable device and the light emission drive IC of the present invention, whose circuit diagram of the resistance circuit is shown in FIG. 4, differs from that of the first embodiment described above in that the bias resistor 11a is embodied as a resistance circuit. That is the point. The bias resistor 11a is configured such that a plurality of resistance elements are connected in series and parallel, and some of the resistance elements can be turned on or off by a switch.

In this case, the setting change of the resistance value is performed by opening / closing each switch, and the resistance value becomes any one of a plurality of / many discrete values. In addition, the resistance value can be relatively finely and finely changed by increasing the number of resistors. Therefore, it is more suitable for an IC than a continuously variable system.

[0047]

[Third Embodiment] FIG. 5 shows a graph of a display panel reflection characteristic and a brightness control characteristic, and the portable device of the present invention has
The difference from the second embodiment is that the control of the first characteristic is introduced for the variable control of the drive power by the brightness adjusting unit 12. In this example, the control of the first characteristic is introduced by modifying the calculation contents of the microprocessor 8 without modifying the brightness adjusting unit 12. That is, when the microprocessor 8 calculates the adjustment value of the brightness adjusting unit 12 based on the output voltage Vo of the optical sensor 2, it does not increase or decrease the adjustment value by simply interlocking with the increase or decrease of the output voltage Vo. Output voltage V at low Vo
Although the adjustment value is increased / decreased in conjunction with the increase / decrease of o, the adjustment value is increased / decreased in the opposite direction to the increase / decrease of the output voltage Vo when the output voltage Vo is high, and the adjustment value is made almost constant in the middle. Has become.

In this case, a reflective panel is used for the display unit 3. In a reflective display panel, the amount of panel reflected light that contributes to display is small when the surroundings are dark, but is sufficiently large when the surroundings are bright (see FIG. 5A).
On the other hand, the light emission amount of the light emitting unit 6 that is used to illuminate the display unit 3 initially increases with an increase in ambient brightness, but stagnates in the middle, and then decreases (see FIG. b)
reference).

The light amounts of the two are combined so that the display section 3 is always easy to see regardless of the ambient brightness.
Thus, according to the present invention, a reflective type display unit can be used for the display unit of the mobile device without impairing the visibility and without wasting battery power.

[0050]

[Fourth Embodiment] FIG. 6 shows a graph of the display panel reflection characteristic and the brightness adjustment characteristic of the portable device of the present invention, which is different from that of the third embodiment. Regarding the variable control, in addition to the control of the first characteristic described above, the control of the second characteristic is also introduced, and which characteristic is to be controlled is selected. Also in this example, the newly added function is embodied by the microprocessor 8.

That is, when the microprocessor 8 calculates the adjustment value of the brightness adjusting section 12 based on the output voltage Vo of the optical sensor 2, the first operation is performed according to the switch setting on the circuit board and the parameter setting of the memory storage. Either the characteristic control or the second characteristic control is reflected. Then, when the control of the first characteristic should be performed, the same calculation as that of the third embodiment described above is performed. On the other hand, when the control of the second characteristic should be performed, the output voltage Vo
Although the adjustment value is increased / decreased in association with the increase / decrease of the output voltage Vo from a low position to a middle position, the adjustment value is made substantially constant at a high output voltage Vo.

In this case, a reflective panel or a semi-transmissive panel is adopted as the display unit 3. When the reflection type is adopted, parameter setting to that effect is performed. Then, also in this case, the brightness adjustment suitable for the reflection type is performed as described above. Further, even when a semi-transmissive type is adopted, the parameter setting to that effect is performed. Then, in this case, the amount of light reflected from the panel that contributes to display is small when the surroundings are dark or in the middle, and slightly increases when the surroundings are bright (see FIG. 6A). On the other hand, the light emitting unit 6 used for illumination of the display unit 3
The amount of light emission of increases at first with respect to the increase of the ambient brightness, and the increase continues halfway, but then becomes stagnant and becomes almost constant (see FIG. 6B).

Also in this case, the light amounts of both are combined so that the display section 3 is always easy to see regardless of the ambient brightness. Thus, according to the present invention, it is convenient to use a reflective type or a semi-transmissive type for the display unit of the mobile device without impairing the visibility and without wasting battery power. Can be used.

[0054]

[Fifth Embodiment] FIG. 7 shows a graph of a display panel reflection characteristic and a brightness adjustment characteristic of the portable device of the present invention, which is different from that of the fourth embodiment. The first characteristic control and the second control described above regarding variable control
The point that not only the characteristic control but also the third characteristic control is added to the selection target. Also in this example, the newly added function is embodied by the microprocessor 8.

That is, when the microprocessor 8 calculates the adjustment value of the brightness adjusting section 12 based on the output voltage Vo of the optical sensor 2, the first operation is performed according to the switch setting on the circuit board and the parameter setting of the memory storage. Any one of the characteristic control, the second characteristic control, and the third characteristic control is reflected. Then, the control of the first characteristic and the second
When the characteristics should be controlled, the same calculation as that of the above-described fourth embodiment is performed. On the other hand, when the control of the third characteristic should be performed, the adjustment value is increased / decreased in association with the increase / decrease of the output voltage Vo from a place where the output voltage Vo is low to a place where the output voltage Vo is high.

In this case, a reflective panel, a semi-transmissive panel or a transmissive panel is adopted as the display section 3. When the reflective type or the semi-transmissive type is adopted, if the parameters to that effect are set, the brightness adjustment suitable for each type is performed as described above. Further, even when the transmissive type is adopted, parameter setting to that effect is performed. Then, in this case, there is almost no panel reflected light amount that contributes to the display regardless of the ambient brightness (FIG. 7).
(See (a)). On the other hand, the light emission amount of the light emitting unit 6 used for illumination of the display unit 3 consistently and monotonically increases from the beginning to the end as the ambient brightness increases (FIG. 7).
(See (b)).

Also in this case, the display section 3 is always easy to see regardless of the ambient brightness. Thus, according to the present invention, the display unit of the portable device may be of a reflective type, a semi-transmissive type or a transmissive type without impairing the visibility and wastefully consuming the battery power. Any convenient one can be used.

[0058]

[Sixth Embodiment] The light emitting drive IC of the present invention, the block diagram of which is shown in FIG. 8, differs from that of the first and second embodiments described above in that the function operation circuit 12 is provided upstream of the PWM circuit 12a.
b is provided. The function calculation circuit 12b is introduced between the serial-parallel conversion unit 14 and the PWM circuit 12a, and performs a function calculation corresponding to the liquid crystal type on the adjustment value sent from the microprocessor 8 to the brightness adjustment unit 12 on the way. The content of the calculation corresponds to the control of the above-mentioned first characteristic when the liquid crystal type is the reflective type, and corresponds to the control of the above-mentioned second characteristic when the liquid crystal type is the semi-transmissive type. When the liquid crystal type is the transmissive type, it corresponds to the control of the above-mentioned third characteristic. The liquid crystal type of the display unit 3 is given from the outside through a dedicated IC pin (terminal) in the illustrated one, but may be given from the microprocessor 8 through the serial-parallel conversion unit 14. .

In this case, the selection and execution of the control of each of the first to third characteristics is left to the light emission drive IC 10, the microprocessor 8 is relieved of the burden, and is influenced by the type of the display unit 3. Since it is sufficient to adjust the brightness using a basic method, the versatility of the program is enhanced and debugging is also facilitated.

[0060]

[Others] In each of the above embodiments, when the microprocessor 8 sends a command to the level adjusting means 11 and the brightness adjusting section 12 via the serial-parallel conversion section 14, the light emission drive is performed. The serial-parallel conversion may be omitted if the IC pin (terminal) of the IC 10 has a margin and parallel transmission can be performed. Further, the calculation of the adjustment value and the calculation of the adjustment value, which have been processed by the microprocessor 8 in each of the above-described embodiments, are also transferred to the light emission driving IC 10, and the light emission driving IC 10
May independently perform brightness adjustment to level adjustment.

[0061]

As is apparent from the above description, in the portable device, the light emission drive IC and the adjusting method of the first solution of the present invention, the optical sensor incorporated for adjusting the brightness is used. By making it possible to calculate the adjustment value of the output level, it is possible not only to save battery power by adjusting the brightness using the photosensor but also to easily adjust the output level of the photosensor. It has a great effect.

In the portable device, the light emission drive IC and the adjusting method according to the second solution of the present invention, since the illumination is made to compensate for the lack of the reflected light, the display unit is of the reflective type. Even in the case of the above, there is an advantageous effect that not only the battery power is saved by the brightness adjustment using the optical sensor, but also the optical sensor output level can be easily adjusted.

Further, in the portable device, the light emission drive IC and the adjusting method of the third means of solving the problems of the present invention, it is possible to selectively use illumination for compensating for the lack of reflected light and illumination for balancing the reflected light. As a result, whether the display unit is a reflective type or a semi-transmissive type saves battery power by adjusting the brightness using an optical sensor, and also has the advantageous effect that the output level of the optical sensor can be easily adjusted. There is.

Further, in the portable device, the light emission drive IC and the adjusting method of the fourth solution of the present invention, there are provided an illumination that compensates for the lack of reflected light, an illumination that balances the reflected light, and an illumination that does not require the reflected light. By making it possible to use properly,
Regardless of whether the display is reflective, semi-transmissive or transmissive, not only battery power is saved by adjusting the brightness using an optical sensor, but also the output level of the optical sensor can be easily adjusted, which is an advantageous effect. Play.

Further, in the portable device, the light emission drive IC and the adjusting method of the fifth solving means of the present invention, the data of a plurality of points / a plurality of points can be easily used when the level is adjusted. Thus, there is an advantageous effect that not only the battery power is saved by the brightness adjustment using the photosensor, but also the photosensor output level can be easily adjusted over a wide range.

[Brief description of drawings]

FIG. 1 shows the configuration of a portable device, a light emission drive IC, and an adjusting method according to a first embodiment of the present invention.
Is an external perspective view, (b) is a side view, (c) is a block diagram of an electronic circuit, and (d) is a circuit diagram of a main part.

FIG. 2 is an explanatory diagram of a situation of adjustment work.

3A and 3B are graphs showing how the optical sensor output level varies, where FIG. 3A is before adjustment and FIG. 3B is after adjustment.

FIG. 4 is a circuit example of a bias resistance of a phototransistor in a second embodiment of the portable device and the light emission drive IC of the present invention.

FIG. 5 shows a third embodiment of the mobile device of the present invention.
(A) is a graph showing the reflection characteristics of the display panel,
(B) is a graph showing the characteristic of the brightness adjustment corresponding to it.

FIG. 6 shows a fourth embodiment of the mobile device of the present invention.
(A) is a graph showing the reflection characteristics of the display panel,
(B) is a graph showing the characteristic of the brightness adjustment corresponding to it.

FIG. 7 shows a fifth embodiment of the mobile device of the present invention.
(A) is a graph showing the reflection characteristics of the display panel,
(B) is a graph showing the characteristic of the brightness adjustment corresponding to it.

FIG. 8 is a block diagram showing a sixth embodiment of the light emission drive IC of the present invention.

[Explanation of symbols]

1 mobile phone (portable device) 2 optical sensor (photodiode, phototransistor, photoelectric conversion means) 3 display unit (display panel such as liquid crystal panel) 4 key (operation member, input member) 5 battery (battery) 6 light emitting unit ( LED, EL, backlight, front light) 7 memory (ROM, EPROM, non-volatile memory) 8 microprocessor (CPU, MPU, control calculation means) 9 A / D conversion circuit (analog-digital conversion means) 10 light emission drive IC (Semiconductor integrated circuit device) 11 Level adjusting means 11a Bias resistance (resistive element, resistance circuit) 11b Amplifier (Amp, output amplifier with variable gain) 12 Brightness adjusting section 12a PWM circuit (pulse width modulation circuit, variable drive power) Means) 12b Function arithmetic circuit (means for selecting and switching characteristics of variable control) 3 Drive Unit (Boosting Circuit, DC-DC Converter, Voltage Stabilizing Circuit) 14 Serial / Parallel Conversion Unit (S / P Conversion, Serial-Parallel Conversion Means) 20 Adjustment Jig (Means to Create Environment in Which Illuminance Changes in a Predetermined Range) ) 21 cover (dark box) 22 light (lighting)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04M 1/24 H04M 1/24 BF term (reference) 2H091 FA41Z FA48X FD22 GA11 LA30 2H093 NC42 NC55 NC56 ND02 ND07 ND39 5K023 AA07 BB04 BB21 HH07 HH08 MM07 5K027 AA11 BB00 FF22 LL02 MM17

Claims (12)

[Claims] 1. A display section, a light emitting section for illuminating the display section, a drive section for generating its drive power from a battery output, a brightness adjusting section for varying the drive power, and an optical sensor for detecting ambient brightness. And a level adjusting means for adjusting the output level of the optical sensor in a portable device that performs variable control of the brightness adjusting unit based on the output of the optical sensor,
A mobile device, comprising: a control calculation unit that selectively performs a process of calculating the adjustment value based on the output of the optical sensor. 2. When the variable control of the brightness adjusting unit is performed based on the output of the optical sensor, the drive power is first increased with respect to the increase of the output of the optical sensor, and then the drive power is gradually decreased. The mobile device according to claim 1, which controls characteristics. 3. The control of the first characteristic and the control of the second characteristic, in which the drive power is first increased and then made constant during the increase of the output of the optical sensor, are selectively performed. The mobile device according to claim 2, wherein the mobile device is a mobile device. 4. The portable device according to claim 2, wherein the control of the third characteristic for monotonically increasing the drive power with respect to the increase of the output of the optical sensor is also performed. machine. 5. The photosensor is a phototransistor, and the level adjusting means variably controls the value of the bias resistance of the transistor when adjusting the output level of the photosensor, and the gain of the output amplifier is also variable. The mobile device according to any one of claims 1 to 4, which is for controlling. 6. A terminal for receiving a battery output, a terminal for sending its driving power to a light emitting unit, a driving unit for generating the driving power from the battery output, and a brightness adjusting unit for varying the driving power. And a terminal for receiving the output of the optical sensor, and a level adjusting means capable of adjusting the output level of the optical sensor. 7. A first characteristic in which when the variable control of the brightness adjusting unit is performed based on the output of the optical sensor, the drive power is first increased with respect to the increase of the output of the optical sensor, and then decreases from the middle. 7. The light emission drive IC according to claim 6, further comprising means for controlling the above. 8. The control of the first characteristic and the control of the second characteristic for increasing the output of the optical sensor and increasing the drive power at the beginning to make it constant from the middle are selectively performed. The light emission drive IC according to claim 7. 9. The light emission according to claim 7, wherein the control of the third characteristic for monotonically increasing the driving power with respect to the increase of the output of the optical sensor is also performed. Drive IC. 10. The level adjusting means has a resistance element or a resistance circuit which becomes a bias resistance when a phototransistor is adopted for the photosensor, and an output amplifier for amplifying the output of the photosensor, 10. When adjusting the output level of the said optical sensor, the resistance value of the said resistance element or the said resistance circuit is variably controlled, and the gain of the said amplifier is also variably controlled, It is characterized by the above-mentioned. The light emission drive IC described in 1. 11. The light emission drive IC according to any one of claims 6 to 10 when adjusting the optical sensor output level of the portable device according to any one of claims 1 to 5. And a control calculation unit that selectively performs a process of calculating the adjustment value of the level adjustment unit based on the output of the optical sensor, and variably controls the brightness adjustment of the illumination of the display unit according to the ambient brightness. When adjusting the optical sensor output level of a battery-powered portable device, the optical sensor output level of the portable device is set such that the portable device is placed in an environment with a predetermined illuminance and the adjustment value calculation process is executed by the control calculation means. Adjustment method. 12. When adjusting the optical sensor output level of the portable device according to claim 5, or incorporating the light emission drive IC according to claim 10, the adjustment value of the level adjusting means is set to the optical sensor. Adjustment of the optical sensor output level of a battery-powered portable device that is provided with a control calculation unit that selectively performs a process of calculating based on the output of the display unit and variably controls the brightness adjustment of the illumination of the display unit according to the ambient brightness. In carrying out the above, the method for adjusting the optical sensor output level of the portable device, wherein the portable device is placed in an environment in which the illuminance changes within a predetermined range and the adjustment value calculation process is executed by the control calculation means.