JP2001350441A - Display device and portable electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically adjust the luminance of a screen in accordance with the ambient brightness in the display device provided with an illuminator. SOLUTION: In a portable terminal 1 in which a reflection type liquid crystal display panel 122 is illuminated by a front light 13 and the luminance of the panel 122 is detectable by a photosensor 14, a CPU 21 stores the detection value of the photosensor 14 in a state in which the luminance of the panel 122 is optimum in a reference value storage area 241 and stores respectively detection values at the upper limit and the lowest limit in an upper limit value storage area 242 and a lowest limit value storage area 243. Moreover, the CPU 21 compares the detection value of the sensor 14 with detection values in a storage device 24 and only when the luminance of the panel 122 becomes equal to or higher than the upper limit value and equal to or lower than the lowest limit value, it adjusts the luminance of the front light 13 so that the detection value of the sensor 14 coincides with the reference value in the reference value storage area 241.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device provided with illumination and a portable electronic device provided with the display device.

[0002]

2. Description of the Related Art Conventionally, LCDs (liquid crystal display devices) are widely used because of their advantages such as thinness and low power consumption. Particularly in recent years, PDA (Personal Digital A)
Portable electronic devices using LCDs, such as ssistants (personal information terminals), have become widespread.

[0003]

SUMMARY OF THE INVENTION Portable electronic devices are:
Since it is used in various places, both outdoors and indoors, the visibility of the screen greatly affects the convenience, but it has been difficult to increase the size of the screen due to the weight reduction.

Therefore, various proposals for improving the visibility of the screen have been made in the past.

For example, Japanese Patent Application Laid-Open Nos. 10-133802 and 11-53096 disclose an input pen used at the time of input with a pen input type terminal device.
An input pen incorporating a light bulb and illuminating a screen is disclosed.

[0006] However, this input pen is useful only when a liquid crystal display screen without an illumination device such as a backlight device is used in a dark place.

[0007] For example, see Japanese Patent Application Laid-Open No. 10-198497.
Japanese Patent Application Laid-Open Publication No. H11-209,086 discloses a liquid crystal display device having a light guide plate on the rear surface of a transmissive liquid crystal display panel for efficiently irradiating light to the entire liquid crystal display panel.

[0008] For example, Japanese Patent Application Laid-Open No. 11-73275 discloses an information processing apparatus in which contrast adjustment and brightness adjustment of a liquid crystal display device can be performed by a simple input operation.

[0009] However, these liquid crystal display devices are:
It is used by manually adjusting the brightness of the display screen. Generally, a portable electronic device is used while a user stands, and it is troublesome to adjust the brightness appropriately. For this reason, the portable electronic device provided with the lighting device for display screen illumination has a problem in that the adjustment of the lighting device is troublesome and the convenience is impaired.

SUMMARY OF THE INVENTION It is an object of the present invention to automatically adjust the brightness of a screen according to the surrounding brightness in a display device provided with lighting.

[0011]

Means for Solving the Problems To solve the above problems, the invention according to claim 1 uses a display screen (for example, FIG. 2).
A light source (for example, the front lights 13, 13 shown in FIG. 1) for illuminating the reflective liquid crystal display panel 122 shown in FIG.
In a display device provided with a photodetector, light detecting means (for example, the optical sensors 14 and 1 shown in FIG.
4) a reference value storage means (for example, a reference value storage area 241 shown in FIG. 3) for storing, as a reference value, a detection value of the light detection means when the brightness of the display screen is optimal; Dimming means for changing the luminance of the light source such that the detection value of the light detection means matches the reference value stored in the storage means (for example, CPU 2 which performs the processing shown in FIG. 6)
1).

Here, the display device is, for example, a PDA
(Persional Digital Assistant: personal information terminal),
It refers to a display device included in various portable electronic devices such as a terminal device for sending and receiving e-mail, and includes a device integrated with a main body and a device connected to the outside of the main body.

According to the first aspect of the present invention, in a display device provided with a light source for illuminating the display screen, the brightness of the display screen is detected by the light detecting means, and the light is detected when the brightness of the display screen is optimal. The detected value of the means is stored in the reference value storage means as a reference value, and the brightness of the light source is changed by the dimming means so that the detection value of the light detection means matches the reference value stored in the reference value storage means. Let it.

Therefore, the brightness of the display screen is detected by the light detecting means, and the brightness of the light source is changed so that the detected value matches the detected value in the optimum state. For this reason, the display screen is maintained at the optimum brightness, so that the display screen can be visually recognized comfortably both in a bright place and in a dark place. Also, there is no need for the user to make manual adjustments. This allows comfortable use regardless of the surrounding environment without performing troublesome operations.

According to a second aspect of the present invention, in the display device of the first aspect, an instruction means (for example, a touch pad 123 shown in FIG. CPU 21 for performing the processing shown in step S2 of FIG. 4 and storage control means (for example, FIG. 4) for storing the detected value of the light detecting means at the timing instructed by the instructing means as the reference value in the reference value storing means. CPU that performs the process shown in step S4
21) is further provided.

According to a second aspect of the present invention, the timing at which the brightness of the display screen is optimal is designated by the designation means, and the detected value of the light detection means at the designated timing is stored in the reference value storage means by the storage control means. Store as a value.

Therefore, when the luminance of the display screen is in an optimum state, an instruction is given by the instruction means, so that the detected value in the optimum state is stored. Thereafter, the brightness of the light source is controlled so as to match the stored detection value, that is, to reproduce the state specified by the specifying means. For this reason, the user only has to give an instruction with the instruction unit when the brightness of the display screen is in an optimal state,
The optimal brightness can be set by a simple operation. The brightness of the display screen that is comfortable when used is based on a comprehensive sense,
Large individual differences between users. For this reason, it is desirable for the user to make settings suitable for himself. ADVANTAGE OF THE INVENTION According to this invention, an optimal state can be set by an intuitive and easy operation, and the display device which is full of convenience and comfortable in use can be provided.

According to a third aspect of the present invention, in the display device according to the second aspect, the dimming instruction means (for example, FIG. 2) for instructing the dimming means to arbitrarily change the luminance of the light source.
It further includes a touch pad 123 shown in (a) and a CPU 21 that performs the processing shown in step S3 in FIG. 4).

According to the third aspect of the present invention, the dimming instruction unit instructs the dimming unit to arbitrarily change the luminance of the light source.

Therefore, the luminance of the display screen can be arbitrarily changed by changing the luminance of the light source. Then, when the brightness of the display screen becomes optimal, an instruction can be given and set by the instruction means in the invention according to the second aspect.
In other words, the brightness of the display screen can be created and set by changing the light source, so that the desired brightness can be set as a reference value even in a dark place or at night.

According to a fourth aspect of the present invention, in the display device according to any one of the first to third aspects, an upper limit storage means (memory) for storing a detection value of the light detection means when the luminance of the display screen is an upper limit. For example, an upper limit value storage area 242 shown in FIG. 3 and a lower limit storage means (for example, a lower limit storage area 243 shown in FIG. 3) for storing the detection value of the light detection means when the luminance of the display screen is at the lower limit. And the dimming means, only when the detection value of the light detection means is not less than the detection value stored in the upper limit storage means or less than the detection value stored in the lower limit storage means, The brightness of the light source is changed so that the detection value of the light detection unit matches the detection value stored in the reference value storage unit.

According to a fourth aspect of the present invention, the detected value of the light detecting means when the brightness of the display screen is at the upper limit is stored in the upper limit storing means, and the detected value of the light detecting means at the time when the brightness of the display screen is at the lower limit is stored. Stored in the lower limit storage means, the dimming means, the light detection means, only when the detection value of the light detection means is greater than the detection value stored in the upper limit storage means or less than the detection value stored in the lower limit storage means, The luminance of the light source is changed so that the detected value matches the detected value stored in the reference value storage means.

Therefore, only when the detected value is equal to or more than the upper limit or equal to or less than the lower limit, the brightness of the light source is changed so as to match the detected value stored in the reference value storage means. Does not change. For this reason, for example, the brightness of the light source is changed when the brightness of the display screen is significantly different from the optimum value, and the brightness of the light source is constant when the brightness is almost the optimum value. This makes it possible to change the brightness of the light source only when necessary, and not to change the brightness of the light source when it is not necessary, which may cause discomfort or impair the feeling of use due to frequent changes in brightness. There is no. For this reason, it is possible to provide a display device that can be used more comfortably by adjusting the light source when necessary while suppressing the change in the luminance of the light source to the minimum number.

According to a fifth aspect of the present invention, there is provided a portable electronic apparatus in which each part is built in a portable main body, the apparatus comprising the display device according to any one of the first to fourth aspects. And

Therefore, since the portable electronic device is provided with a display device capable of maintaining the brightness of the display screen in a comfortable state, the portable electronic device can be used in an environment where the visibility of the display screen is easily reduced, such as in a dark place or outdoors. Even if there is, it can be used comfortably. For this reason, even in a severe use environment, it is possible to provide a portable electronic device that has high visibility of a display screen and can be used comfortably.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, the configuration will be described. FIG. 1 is an external perspective view illustrating a configuration of a mobile terminal 1 according to an embodiment of the present invention. As shown in FIG. 1, a portable terminal 1 includes a main body case 11, a display device 12, front lights 13, 1.
3. Each component of the optical sensors 14 and 14 is provided. FIGS. 2A and 2B are cross-sectional views showing the configuration of the mobile terminal 1 in more detail. FIG. 2A is a cross-sectional view taken along line AA ′ in FIG. It is sectional drawing in a line.

The display device 12 is installed in an opening provided substantially at the center of the front surface of the main body case 11, and as shown in FIG. 2A, the reflection member 121 and the reflection type liquid crystal display panel 12 are provided.
2 and a touch pad 123.

In the display device 12, the main body case 11
The touch pad 123, the reflection type liquid crystal display panel 122, and the reflection member 121 are disposed in this order from the front side. The reflection type liquid crystal display panel 122 is a reflection type liquid crystal display panel that transmits external light incident from the front surface of the main body case 11 and transmits light from the reflection member 121. Note that the number of display colors and the number of display gradations of the reflective liquid crystal display panel 122 are arbitrary.

The reflection member 121 is provided on the back side of the reflection type liquid crystal display panel 122. As shown in FIGS. 2A and 2B, the reflecting member 121 has a shape in which concave portions and convex portions extending along the vertical direction of the main body case 11 of FIG. 1 are alternately arranged. The portion having the convex portion is a transparent or translucent member made of glass or a synthetic resin. The reflection member 121 includes a reflection plate (not shown) made of aluminum or the like on the rearmost side.

Then, external light that is transmitted through the reflection type liquid crystal display panel 122 and reflected is reflected. Also, the reflection member 121
Irradiates light from front lights 13, 13 to be described later toward a reflective liquid crystal display panel 122. As described above, since the reflecting member 121 includes the concave portion and the convex portion, external light transmitted through the reflective liquid crystal display panel 122 and incident thereon, and light from the front lights 13 and 13 are all reflective members. 121, the reflection member 1
The reflection liquid crystal display panel 122 is irradiated with a substantially uniform light amount over the entire surface of the liquid crystal display panel 122.

The touch pad 123 is attached to the surface of the reflective liquid crystal display panel 122, and has a transparent electrode, a resistive film, and the like. The touch pad 123 detects the presence or absence of contact with the surface by a circuit (not shown), and when the touch pad 123 is contacted, acquires the relative coordinates of the contact position.

In this embodiment, as shown in FIGS. 1 and 2, the touch pad 123 has the same size as the front opening of the main body case 11, and the reflection member 121 and the reflection type liquid crystal display panel 122 have the same size. , Which are larger than the opening of the main body case 11.

The front lights 13 are provided with a light source such as a cold-cathode tube, an EL (electroluminescence) element, and an LED (light emitting diode).
Reference numeral 22 denotes a light for illuminating from the front side. The front lights 13 and 13 are provided inside the main body case 11 so as to face the surface of the reflective liquid crystal display panel 122, and are provided so as not to be exposed from the opening of the main body case 11.

The optical sensors 14, 14 are sensors for detecting the brightness of the surface of the reflective liquid crystal display panel 122, and the detection surfaces of the optical sensors 14, 14 are reflective liquid crystal display panels 122.
And is facing. The optical sensors 14 and 14 are arranged so as not to be exposed from the opening of the main body case 11 so as to be aligned with the front lights 13 and 13.

FIG. 3 shows a control system 2 of the portable terminal 1 shown in FIG.
FIG. 3 is a block diagram showing the configuration of FIG. As shown in FIG. 3, the control system 2 includes a CPU 21, a ROM 22, a RAM 2
3, storage device 24, illumination control unit 25, display control unit 26,
The input control unit 27 and the light detection unit 28 are connected to each other via a bus 25. Lighting control unit 2
5, the display control unit 26, the input control unit 27, and the light detection unit 28 include front lights 13, 13, a reflective liquid crystal display panel 122, a touch pad 123, and a light sensor 1
4, 14 are connected respectively.

The CPU 21 reads various control programs stored in the ROM 22, develops them in the RAM 23, and executes them to control each unit of the CPU 21.

More specifically, the CPU 21 includes a storage device 24
The display controller 26 generates data stored therein and display information for displaying various processing results, outputs the generated information to the display controller 26, and causes the display controller 26 to display various screens on the reflective liquid crystal display panel 122. In addition, the CPU 21 controls the touch pad 1
When the input operation at 23 and the detection signal indicating the operation position are input from the input control unit 27, the display contents of the reflective liquid crystal display panel 122 at the operation position are acquired, and the contents of the input operation at the touch pad 123 are displayed. Determine.

Further, the CPU 21 adjusts the wells of the front lights 13 and 13 by appropriately changing the voltage value supplied from the illumination control unit 25 to the front lights 13 and 13, The detection values obtained by the optical sensors 14 and 14 are obtained.

Then, the CPU 21 controls the touch pad 12
By executing the program in the ROM 22 in accordance with the input operation in Step 3, for example, the telephone directory data stored in the storage device 24 is read out, and the name and telephone number of the contact set in the telephone directory data are reflected. List on the liquid crystal display panel 122 and addition of telephone directory data according to the input contents on the touch pad 123.
By performing various processes such as deletion and change, the telephone directory data in the storage device 24 is updated. Also, for example, the CPU 21
The schedule management processing is executed, the calendar data stored in the storage device 24 and the schedule data stored in association with the calendar data are read, and the schedule is displayed on the reflective liquid crystal display panel 122 as a list. Then, the schedule data is edited according to the input content on the touch pad 123, and the schedule data in the storage device 24 is updated.

When the operation of the portable terminal 1 is started, the CPU 21 reads out and executes the initial setting processing program from the ROM 22, adjusts the luminance of the reflective liquid crystal display panel 122 to an appropriate luminance, and inputs "OK". If
The values detected by the optical sensors 14 at that time are stored in the reference value storage area 241 as reference values of the luminance of the reflective liquid crystal display panel 122.

Further, in the initial setting process, the CPU 21 performs an input operation on the touch pad 123 to
When the upper and lower limits of the luminance of the reflective liquid crystal display panel 122 are determined, the detection values of the optical sensors 14 at the time of the determination are stored in the upper limit storage area 242 and the lower limit storage area 2.
43, respectively.

Then, the CPU 21 executes a lighting control process when the portable terminal 1 is used, acquires the detection values of the optical sensors 14, 14, and when the detected values are equal to or more than the upper limit value stored in the upper limit storage area 242, Alternatively, the lower limit storage area 24
When the brightness is equal to or lower than the lower limit value stored in the reference value 3, the brightness of the front lights 13, 13 is adjusted until the brightness reaches the reference value stored in the reference value storage area 241.

The ROM 22 stores various control programs and data executed by the CPU 21 in a format readable by the CPU 21.

The RAM 23 forms a work area for temporarily storing various control programs executed by the CPU 21 and data related to these programs.

The ROM 22 and the RAM 23 are made of, for example, semiconductor storage elements.
1 may be mounted on the same substrate, or may be mounted in the same package as the CPU 21.

The storage device 24 is made of an optical or magnetic recording medium or a semiconductor storage element, and stores various programs and data. The contents stored in the storage device 24 can be arbitrarily rewritten.

For example, the storage device 24 stores calendar data relating to the date, schedule data associated with the calendar data, and telephone directory data associated with telephone numbers and contact names. Mobile terminal 1
The data for realizing the various functions is stored.

The storage device 24 stores the reference value storage area 2
41, upper limit storage area 242 and lower limit storage area 24
3 storage areas.

In the reference value storage area 241, when an optimal state of the brightness of the reflective liquid crystal display panel 122 is designated by an input operation on the touch pad 123 in the initial setting process, the optical sensor 14 in the designated state is designated. , 14 are stored. The upper limit value storage area 242 and the lower limit value storage area 243 store the detection values of the optical sensors 14 and 14 at the upper limit and the lower limit of the luminance of the reflective liquid crystal display panel 122, which are similarly set in the initial setting process.

Before the portable terminal 1 performs the initial setting process, default setting values are stored in the reference value storage area 241, the upper limit storage area 242, and the lower limit storage area 243 in advance. I have.

The illumination control unit 25 performs control such as changing the voltage supplied to the front lights 13 and 13 according to the control of the CPU 21 to thereby control the front lights 1.
3 and 13 are controlled.

The display controller 26 drives and controls the reflective liquid crystal display panel 122 based on display information input from the CPU 21 to display various screens on the reflective liquid crystal display panel 122.

When a touch operation is performed on the touch pad 123, the input control unit 27 specifies an operation position and outputs an operation signal indicating the operation position to the CPU 21.

The light detection unit 28 performs various processes such as detection of abnormal values such as a maximum value and a minimum value and averaging at predetermined time intervals while acquiring the detection values of the optical sensors 14 and 14.
The detected values of the optimized optical sensors 14, 14 are stored in the CPU 21.
Output to Thus, when the detection value of the optical sensors 14 and 14 changes abnormally, such as when the detection value changes extremely for a very short time, the CPU 2 follows the change.
Troubles such as abnormal operation of 1 can be prevented.

FIG. 4 is a flowchart showing an initial setting process executed by the CPU 21, and FIG. 5 is a flowchart showing an illumination control process. FIG. 6 shows the reflective liquid crystal display panel 122 in the initial setting process of FIG.
3A shows an example of a screen displayed in FIG.
FIG. 1B shows an upper limit / lower limit setting screen 32. FIG. Hereinafter, the operation of the present embodiment will be described with reference to FIGS. 4 to 6.

In the initial setting process shown in FIG.
Reference numeral 21 denotes the front lights 13 and 13 according to the set values stored in the reference value storage area 241 by default.
Is turned on, and the initial setting screen is displayed on the reflective liquid crystal display panel 12.
2 (step S1).

Then, the CPU 21 controls the touch pad 12
When the input operation in step 3 is detected, the input content is "OK".
It is determined whether or not (step S2). In other words, if "OK" is input, it is an instruction that the current luminance of the reflective liquid crystal display panel 122 can be set to the reference value.

If the input is not "OK" (step S2; No), the input content is an instruction to increase or decrease the brightness of the reflective liquid crystal display panel 122. Therefore, the CPU 21 proceeds to step S3, changes the brightness of the front lights 13, 13 according to the input instruction content, and returns to step S2 to wait for an input operation.

If "OK" has been input (step S2; Yes), the CPU 21 causes the photodetectors 28 to acquire the detection values of the photosensors 14 and 14,
The reference value is stored in the reference value storage area 241 (step S4).

Thereafter, the CPU 21 switches the display screen displayed on the reflective liquid crystal display panel 122,
An upper / lower limit setting screen is displayed (step S5). On the upper / lower limit setting screen displayed here, three types of inputs of an allowable width input, an upper limit input, and a lower limit input can be performed as in the example shown in FIG. 6B. Step S
In step 4, a predetermined range centered on the reference value stored in the reference value storage area 241 is input as an allowable range. Specifically, a deviation from the reference value, such as ± 10% from the reference value, is input. According to this allowable width input, the upper limit and the lower limit can be input collectively. In the upper limit input and the lower limit input, an allowable upper limit value and an allowable lower limit value are input.

When detecting an input on the touch pad 123, the CPU 21 determines whether or not the input is an input relating to an allowable width input (step S6). If the input is not an input relating to the allowable width input, the CPU 21 proceeds to step S
The process proceeds to step S10, and if the input is for an allowable width input, the process proceeds to step S7.

In step S7, the CPU 21 determines whether or not the input content is an "OK" instruction. If the input content is not an "OK" instruction, the CPU 21 inputs an instruction to enlarge or reduce an allowable width. In step S8, the allowable width displayed on the reflective liquid crystal display panel 122 is changed according to the instruction, and the flow returns to step S7 to wait for an input operation.

When "OK" is input in step S7, the CPU 21 determines the upper limit value and the lower limit value from the reference value stored in the reference value storage area 241 based on the currently set permissible width. Is calculated and the upper limit storage area 2
42 and the lower limit storage area 243.

On the other hand, if it is determined in step S6 that the input content is not an input related to the allowable width input, the CPU 21 proceeds to step S10 to determine whether the input content is an input related to the upper limit value. Here, if the input is related to the upper limit value, the CPU 21 further determines whether or not the input content is “apply” (step S11). “Apply” is an instruction to maintain the state where processing can be continued while executing the input instruction temporarily. Here, the value being set is set as the upper limit value, but the lower limit value is subsequently set. This is an instruction to keep the state in which the operation can be performed.

If the input content is not “apply” in step S 11, the input content is
CPU 21 is an instruction to increase or decrease the brightness of
The front lights 13 and 13 are dimmed according to the instruction (step S12), and the process returns to step S11 to wait for an input operation.

When "apply" is input, the CPU 2
1 shifts to step S13, where the current optical sensor 14,
The detection value at 14 is acquired and stored in the upper limit storage area 242 as the upper limit. Then, when the input operation is performed, the CPU 21 determines whether or not the input content is an “end” instruction (step S14). If the input content is the “end” instruction, the CPU 21 ends the process. Returns to step S10.

If the input content is not an instruction relating to “upper limit” in step S10, the CPU 21 proceeds to step S10.
The process proceeds to 15 to determine whether or not the input content is “apply”.

If the input content is not “apply” in step S15, the input content is
CPU 21 is an instruction to increase or decrease the brightness of
The front lights 13 and 13 are dimmed according to the instruction (step S16), and the process returns to step S15 to wait for an input operation.

When the instruction “Apply” is input, C
The PU 21 proceeds to step S17, acquires the current detection values of the optical sensors 14, 14, and stores them in the lower limit storage area 243 as the lower limit. Then, when the input operation is performed, the CPU 21 determines whether or not the input content is an “end” instruction (step S18). If the input content is the “end” instruction, the CPU 21 ends the process. Returns to step S10.

As described above, in the initial setting process,
A reference value, an upper limit value, and a lower limit value of the luminance of the reflective liquid crystal display panel 122 are set, and stored in the reference value storage area 241, the upper limit storage area 242, and the lower limit storage area 243, respectively.

FIG. 5A is a diagram showing an example of the initial setting screen 31 displayed in step S1 of the initial setting process in FIG. On the initial setting screen 31, a guidance message 311 for urging the user to set a reference value is displayed.
A brightening button 312, a darkening button 313, and an “OK” button 314 are displayed as areas for performing operation inputs.

When the light-intensifying button 312 is operated, the process shown in step S3 in FIG.
When the brightness of the front lights 13 and 13 is increased and the dimming button 313 is operated, the brightness of the front lights 13 and 13 is similarly reduced.

When the "OK" button 314 is operated in a state where the brightness of the reflective liquid crystal display panel 122 is the most comfortable brightness, that is, the optimum value, the user can see FIG.
By the processing shown in step S4, the detection values of the optical sensors 14 and 14 in this state are stored in the reference value storage area 241.

FIG. 5B is a diagram showing an example of the upper / lower limit setting screen 32 displayed in step S5 of FIG.
The upper / lower limit setting screen 32 includes an allowable width input area 32.
a, upper limit value input area 32b and lower limit value input area 3
It is divided into three areas 2c.

The allowable width input area 32a is an area operated when setting the upper and lower limits of the brightness of the reflective liquid crystal display panel 122 as a range having a predetermined width from the reference value. Can be input, and is operated in the processing from step S6 to step S9 in FIG. In the example shown in FIG. 5B, the allowable width is displayed as a percentage indicating the ratio of deviation from the reference value. The user can set the upper limit and the lower limit by adjusting the ratio to a desired value and operating the “OK” button.

The upper limit value input area 32b is an area for setting only the upper limit value. The upper limit value is displayed as a percentage indicating the ratio of the deviation from the reference value. Buttons, an “apply” button, an “end” button, and the like are displayed. Upper limit value input area 32
In FIG. 4B, when the ratio is changed, step S1 in FIG.
The brightness of the front lights 13, 13 is changed by the process of 2. Then, when the “apply” button is pressed when the brightness to be set as the upper limit is reached, only the upper limit is stored in the upper limit storage area 242 by the process of step S13 in FIG. At this time, the screen cannot be switched.

The lower limit value input area 32c is an area for setting only the lower limit value. The lower limit value is displayed as a percentage indicating the ratio of the deviation from the reference value. , An "apply" button, an "end" button, and the like. In the lower limit value input area 32c,
When the above ratio is changed, the brightness of the front lights 13, 13 is changed by the process of step S16 in FIG.
Then, when the brightness reaches the lower limit,
When the “apply” button is pressed, step S17 in FIG.
By the above processing, only the upper limit is stored in the upper limit storage area 242. At this time, the screen cannot be switched.

When the "end" button in the upper limit value input area 32b or the lower limit value input area 32c is operated, it is determined that all the settings on the upper limit / lower limit setting screen 32 have been completed, and the screen is switched.

Next, the illumination control process will be described with reference to FIG. This lighting control process is executed at regular intervals during the operation of the mobile terminal 1 during normal use.

At step S21 in FIG. 6, the CPU 21
The detection values of the optical sensors 14 are obtained by controlling the light detection unit 28. Then, the CPU 21 proceeds to step S22, and determines whether or not the acquired detection value is equal to or larger than the upper limit stored in the upper limit storage area 242.

If it is determined in step S22 that the detected value is equal to or larger than the upper limit, the CPU 21 proceeds to step S23, reduces the brightness of the front lights 13, 13 by a predetermined value, and proceeds to step S24. In step S <b> 24, the detection values of the optical sensors 14 and 14 are acquired again, and are compared with the reference values stored in the reference value storage area 241. And when it matches with the reference value, the process is terminated as it is,
If they do not match, the process returns to step S23, and the brightness of the front lights 13, 13 is reduced again. That is,
By repeating the processing of steps S23 and S24, the dimming of the front lights 13, 13 is performed until the luminance of the reflective liquid crystal display panel 122 matches the reference value.

On the other hand, in step S22, the optical sensors 14,
If the detected value is less than the upper limit, the CPU 21 proceeds to step S25 to determine whether the acquired detected value is equal to or smaller than the lower limit stored in the lower limit storage area 243. Here, if the lower limit is exceeded, the CPU 21
Ends this processing. Also, if it is below the lower limit,
The CPU 21 proceeds to step S26 to lower the brightness of the front lights 13, 13.

Then, the CPU 21 proceeds to step S27 to acquire the detection values of the optical sensors 14, 14, and determines whether or not the acquired detection values match the reference values stored in the reference value storage area 241. If they match, the process ends. If they do not match, the process returns to step S26 to increase the brightness of the front lights 13, 13 again. That is, by repeating the processing of step S26 and step S27, the reflective liquid crystal display panel 122
Until the brightness of the front light 13 matches the reference value.
13 is brightened.

Then, the processing shown in FIG. 6 is repeatedly executed at predetermined time intervals during the operation of the portable terminal 1, so that the luminance of the reflective liquid crystal display panel 122 is stored in the upper limit storage area 242. Upper limit and lower limit storage area 24
It is kept between the lower limit value stored in 3. The dimming of the front lights 13 and 13 is controlled by the reflective liquid crystal display panel 1.
Since the adjustment is performed when the luminance of the pixel 22 becomes equal to or more than the upper limit value or equal to or less than the lower limit value, there is no problem that the dimming is frequently performed and the usability is rather deteriorated. Further, when the brightness of the reflective liquid crystal display panel 122 becomes equal to or more than the upper limit value or equal to or less than the lower limit value, the dimming of the front lights 13 is performed until the brightness of the reflective liquid crystal display panel 122 becomes equal to the reference value. Therefore, it is possible to provide a near-optimal operation environment.

As described above, according to the portable terminal 1 in the embodiment of the present invention, the detection values of the optical sensors 14 and 14 when the luminance of the reflective liquid crystal display panel 122 is optimal are stored in the reference value storage area 241. In the reference value storage area 24.
The brightness of the front lights 13, 13 is adjusted so that the detection value stored in 1 and the detection values of the optical sensors 14, 14 match.

Therefore, while the portable terminal 1 is in use, the reflection type liquid crystal display panel 122 is kept at the optimum brightness, so that good visibility is maintained even in a dark place or a bright place. Thereby, the portable terminal 1 can be used comfortably regardless of the use environment.

The upper limit storage area 242 stores the optical sensor 1 when the brightness of the reflective liquid crystal display panel 122 is the upper limit.
The detection values of the optical sensors 14 and 14 when the luminance of the reflective liquid crystal display panel 122 is at the lower limit are stored in the lower limit storage area 243. And
The detection values of the optical sensors 14 and 14 are stored in the upper limit storage area 242.
The brightness of the front lights 13, 13 is adjusted only when the detected value is equal to or more than the detected value of the lower limit value storage area 243.

As a result, the portable terminal 1 can be used stably without frequently adjusting the brightness of the front lights 13, 13 unless it is unnecessary. In addition, when the brightness of the reflective liquid crystal display panel 122 greatly changes and the brightness needs to be adjusted, the brightness of the front lights 13 and 13 is adjusted. The portable terminal 1 which can be provided.

Further, the detection values stored in the reference value storage area 241, the upper limit value storage area 242, and the lower limit value storage area 243 adjust the brightness of the reflective liquid crystal display panel 122 by the initial setting process shown in FIG. It can be easily set by giving an instruction. For this reason, it is possible to perform the optimal setting for the user by intuitive operation,
The portable terminal 1 is highly convenient and can be used comfortably.

In the above embodiment, FIG.
Initial setting screen 31 and upper / lower limit setting screen 32 shown in FIG.
The upper limit, the lower limit, and the reference value are set in a state where is displayed on the reflective liquid crystal display panel 122. However, the present invention is not limited to this. An input area for setting a reference value may be provided in one corner of the liquid crystal display panel 122, and the reference value may be set at any time in accordance with an operation in this area.

In the above embodiment, the front lights 13, 13 and the reflection type liquid crystal display panel 122 are used.
The brightness was used as a measure of the brightness of the light source. In addition, for example, various values such as luminous intensity (candela, etc.), illuminance (lux, etc.), May be expressed in the unit system defined in the above. The definition, measurement method, unit, and the like are not particularly limited. For this reason, for example, the detection values of the optical sensors 14 and 14 may be the voltage values themselves output by the optical sensors 14 and 14 including the photodiodes and the phototransistors, or use the various unit systems described above. It may be a value.

In the above embodiment, the illumination control unit 25 changes the voltage supplied to the front lights 13, 13 to change the voltage applied to the front lights 13, 13.
However, the present invention is not limited to this. When the front lights 13 have a plurality of light sources, the brightness is adjusted by changing the number of light sources that emit light. Alternatively, another method may be used.

Further, in place of the front lights 13 and 13, a backlight may be provided on the back surface of the reflective liquid crystal display panel 122. In addition, the specific shape of the main body case 11 may be appropriately changed. Needless to say, it can be changed to

[0095]

According to the first aspect of the present invention, the luminance of the display screen is detected by the light detecting means, and the luminance of the light source is changed so that the detected value matches the detected value in the optimum state. . For this reason, the display screen is maintained at the optimum brightness, so that the display screen can be visually recognized comfortably both in a bright place and in a dark place. Further, since there is no need for the user to make manual adjustments, it is possible to use the apparatus comfortably regardless of the surrounding environment without performing any troublesome operation.

According to the second aspect of the present invention, when the luminance of the display screen is in the optimum state, the instruction is given by the instruction means, and the detected value in the optimum state is stored. Thereafter, the brightness of the light source is controlled so as to match the stored detection value, that is, to reproduce the state specified by the specifying means. For this reason, the user only has to give an instruction with the instruction means when the brightness of the display screen is in the optimum state, and the optimum brightness can be set by a simple operation. Since the brightness of the display screen that is comfortable when used is based on a comprehensive sense, there is a large individual difference among users. For this reason, it is desirable for the user to make settings suitable for himself. ADVANTAGE OF THE INVENTION According to this invention, an optimal state can be set by an intuitive and easy operation, and the display device which is full of convenience and comfortable in use can be provided.

According to the third aspect of the present invention, the luminance of the display screen can be arbitrarily changed by changing the luminance of the light source. Then, when the brightness of the display screen becomes optimal, an instruction can be given and set by the instruction means in the invention according to the second aspect. In other words, by changing the light source, you can create and set the optimal brightness of the display screen,
A desired luminance can be set as a reference value even in a dark place or at night.

According to the fourth aspect of the present invention, only when the detected value is equal to or more than the upper limit or equal to or less than the lower limit, the brightness of the light source is changed so as to match the detected value stored in the reference value storage means. The brightness of the light source is not changed between the lower limit and the lower limit. For this reason, for example, the brightness of the light source is changed when the brightness of the display screen is significantly different from the optimum value, and the brightness of the light source is constant when the brightness is almost the optimum value. This makes it possible to change the brightness of the light source only when necessary, and not to change the brightness of the light source when it is not necessary, which may cause discomfort or impair the feeling of use due to frequent changes in brightness. There is no. For this reason, it is possible to provide a display device that can be used more comfortably by adjusting the light source when necessary while suppressing the change in the luminance of the light source to the minimum number.

According to the fifth aspect of the present invention, the portable electronic device is provided with a display device capable of maintaining the brightness of the display screen in a comfortable state. It can be used comfortably even in an environment where visibility tends to decrease. For this reason, even in a severe use environment, it is possible to provide a portable electronic device that has high visibility of a display screen and can be used comfortably.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing a configuration of a mobile terminal 1 according to an embodiment to which the present invention is applied.

FIG. 2 is a sectional view showing a configuration of the mobile terminal 1 of FIG. 1,
(A) is sectional drawing in the AA 'line of FIG. 1,
FIG. 2B is a sectional view taken along line BB ′ in FIG.

FIG. 3 is a block diagram showing a configuration of a control system 2 of the portable terminal 1 of FIG.

FIG. 4 is a flowchart showing an initial setting process executed in the portable terminal 1 of FIG.

5A and 5B are diagrams illustrating an example of a screen displayed in the initial setting process of FIG. 4; FIG. 5A illustrates an initial setting screen 31 and FIG. 5B illustrates an upper / lower limit setting screen 32;

FIG. 6 is a flowchart showing a lighting control process executed in the portable terminal 1 of FIG.

[Explanation of symbols]

 Reference Signs List 1 mobile terminal 11 main body case 12 display device 121 reflective member 122 reflective liquid crystal display panel 123 touch pad 13 front light 14 optical sensor 2 control system 21 CPU 22 ROM 23 RAM 24 storage device 241 reference value storage region 242 upper limit value storage region 243 Lower limit value storage area 25 Bus 31 Initial setting screen 32 Upper / lower limit setting screen

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/34 G09G 3/34 J 5G435 3/36 3/36 5K023 H04M 1/02 H04M 1/02 A / / G09G 5/00 550 G09G 5/00 550C 5/10 5/10 B H05B 37/02 H05B 37/02 DF term (reference) 2H093 NC42 NC50 NC55 NC66 ND02 ND07 NE06 3K073 AA13 AA52 AA75 AA82 AB07 BA26 BA28 CA05 CC12 CE12 CE17 CF16 CF17 CG02 CH23 CJ22 CM07 5C006 AF51 AF53 AF54 AF69 BF39 EA01 FA54 5C080 AA10 BB05 DD03 EE28 JJ01 JJ02 JJ06 JJ07 KK02 KK07 5C082 AA00 AA01 BA02 BA12 CA11 CA81 CB01 CB03 AE03 BB03 AE01 HH07 MM07

Claims (5)

[Claims] 1. A display device provided with a light source for illuminating a display screen, wherein: a light detecting means for detecting luminance of the display screen; and a detection value of the light detecting means when the luminance of the display screen is optimal. Reference value storage means for storing as a reference value; and dimming means for changing the brightness of the light source so that the detection value of the light detection means matches the reference value stored in the reference value storage means. A display device, comprising: 2. An instructing means for instructing a timing at which the brightness of the display screen is optimal, and a memory for storing a detection value of the light detecting means at a timing instructed by the instructing means in the reference value storing means as a reference value. The display device according to claim 1, further comprising: control means. 3. The display device according to claim 2, further comprising a dimming instruction unit that arbitrarily changes the luminance of the light source by instructing the dimming unit. 4. An upper limit storing means for storing a detection value of the light detecting means when the luminance of the display screen is an upper limit, and a detecting value of the light detecting means when the luminance of the display screen is a lower limit. A lower limit storage unit, wherein the dimming unit is configured such that, when the detection value of the light detection unit is equal to or greater than the detection value stored in the upper limit storage unit or equal to or less than the detection value stored in the lower limit storage unit. 4. The method according to claim 1, wherein the brightness of the light source is changed so that only the detection value of the light detection unit matches the detection value stored in the reference value storage unit. Display device. 5. A portable electronic device in which each part is built in a portable main body, the portable electronic device comprising the display device according to claim 1. .