JP2011028183A - Portable electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display a screen with less glaring without compromising visibility. <P>SOLUTION: Portable electronic equipment has: a transparent display part 34 having a display surface; an emission part 35a which emits light directly or indirectly onto the display surface from the back with a predetermined amount of light; an optical sensor part 37 which measures the ambient brightness; an image processing part 38 which processes an image displayed on the display surface; a brightness correction part 39 which corrects brightness of the image processed by the image processing part 38; and a control part 42 which controls the emission part 35a to emit lower amount of light than that in a first mode based on the ambient brightness measured by the optical sensor part 37 and which controls the brightness correction part 39 to correct the degree of brightness of the image according to the amount of light when a second mode is selected in a mode selection part 40. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a portable electronic device that adjusts the amount of light of an irradiation unit according to ambient brightness.

  2. Description of the Related Art Conventionally, there is a portable electronic device having a function of adjusting the amount of light of an irradiation unit based on ambient brightness measured by an optical sensor unit (Patent Document 1). For example, when the surroundings are bright, the portable electronic device disclosed in Patent Document 1 is adjusted to increase the light amount of the irradiation unit to such an extent that the screen can be visually recognized. Further, when the surroundings are dark, the light amount of the irradiation unit is adjusted to a level that does not make it difficult to see the screen because it is too bright.

JP 2004-357193 A

  Since the portable electronic device disclosed in Patent Document 1 is not considered for a person (for example, an elderly person) who easily feels glare (dazzle), irradiation is simply performed according to the ambient brightness. The light quantity of the part is adjusted, and there is a possibility that the display is dazzling and difficult to see for these persons.

  In the portable electronic device, in order to reduce glare against the portable electronic device disclosed in Patent Document 1 described above, the light intensity of the irradiation unit is made lower than the normal irradiation amount to darken the screen Can be considered.

  However, when the portable electronic device is configured in this way, the glare can be reduced, but the darkness of the screen causes a problem of impairing the visibility of the screen.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a portable electronic device that can perform screen display with reduced glare without impairing visibility.

  A portable electronic device according to the present invention includes a transmissive display unit having a display surface, an irradiation unit that irradiates the display surface directly or indirectly from the back surface with a predetermined light amount, and light for measuring ambient brightness. A sensor unit, an image processing unit that processes an image displayed on the display surface, a brightness correction unit that corrects the brightness of an image processed by the image processing unit, and ambient brightness measured by the optical sensor unit Based on the first mode, the first mode in which the amount of light is determined, and the ambient light level measured by the optical sensor unit, the amount of light suppressed to be lower than that in the first mode is determined. A mode selection unit for selecting a second mode; and when the second mode is selected in the mode selection unit, the first mode is selected based on ambient brightness measured by the optical sensor unit. Determined by mode 2 And it controls the irradiation unit to irradiate light quantity, and a control unit for controlling the brightness correction unit to correct according to the degree of brightness of the image to the light quantity.

  The portable electronic device includes a light amount changing unit that can change the light amount determined in the first mode and the second mode in a stepwise manner, and the light amount changing unit is in the second mode. It is preferable that the amount of light can be changed more finely than in the first mode.

The portable electronic device includes an application detection unit that detects an attribute of an application to be activated, and the control unit is configured to perform a predetermined application by the application detection unit when the second mode is selected. Is detected, the light amount suppressed to be lower than the light amount determined in the second mode is determined, and the second mode is determined based on the ambient brightness measured by the optical sensor unit. 3. The illumination unit is controlled to irradiate with a light amount that is suppressed to be lower than the light amount determined in step 3, and the lightness correction unit is controlled to correct the brightness level of the image according to the light amount. Portable electronic devices.
It is preferable.

  Moreover, it is preferable that the light quantity changing unit can change the light quantity according to the type of application detected by the application detection unit.

  Further, it is preferable that the brightness correction unit measures the brightness of each pixel constituting the image, selects a pixel having a brightness lower than a predetermined brightness, and corrects the brightness level of the selected pixel in accordance with the amount of light.

  ADVANTAGE OF THE INVENTION According to this invention, the portable electronic device which can perform the screen display which reduced glare, without impairing visibility can be provided.

It is a perspective view which shows the mobile phone of one Embodiment of this invention in an open state. It is a figure explaining the liquid crystal module which comprises a display. It is a functional block diagram explaining the function of the mobile telephone of this embodiment. It is a figure which shows the relationship between the surrounding brightness and the light quantity of a backlight in "normal mode" and "gentle light quantity mode." It is a figure which shows the relationship between the light quantity in the "gentle light quantity mode", and the brightness | luminance correction. It is a flowchart which shows operation | movement of the mobile telephone of this embodiment. It is a figure explaining the display of the display at the time of "gentle light quantity mode" selection.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the basic structure of a mobile phone which is an embodiment of the mobile electronic device of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a mobile phone 1 according to an embodiment of the present invention in an open state. FIG. 2 is a diagram illustrating the liquid crystal module 35 constituting the display 34. The mobile phone 1 according to the present embodiment is configured to display a screen by a liquid crystal display (LCD) system. The mobile phone 1 according to the present embodiment is configured as a so-called transmissive liquid crystal display that performs display by irradiating light from the back of the screen among liquid crystal displays.

  As shown in FIG. 1, the mobile phone 1 according to the present embodiment is a foldable mobile phone 1, which is an operation unit side body 2 having a substantially rectangular parallelepiped shape, a display unit side body 3 having a substantially rectangular parallelepiped shape, And a connecting portion 4 that connects the operation unit side body 2 and the display unit side body 3. Note that the cellular phone 1 according to the present embodiment is configured as the foldable cellular phone 1, but is not limited to this, and one casing is formed from a state in which the operation unit side body 2 and the display unit side body 3 are overlapped. A slide type in which the body is slid in one direction, and a rotary type in which one case is rotated around an axis along the overlapping direction of the operation unit side case 2 and the display unit side case 3 (Turn type) or the like may be used.

  An upper end portion of the operation unit side body 2 and a lower end portion of the display unit side body 3 are connected to each other through a connection unit 4 so as to be opened and closed. That is, the connection part 4 connects the display part side housing | casing 3 and the operation part side housing | casing 2 so that opening and closing is possible centering on an opening-and-closing axis | shaft. The mobile phone 1 is configured such that the operation unit side body 2 and the display unit side body 3 and the display unit side body 3 connected via the connection unit 4 are relatively rotated (rotated), thereby displaying the operation unit side body 2 and the display. The display unit side housing 3 is deformed into a state in which the operation unit side housing 2 and the display unit side housing 3 are folded (closed state).

  The operation unit side body 2 includes an operation unit 11 and a voice input unit 12. The operation unit 11 is a function setting operation key 13 for operating various functions such as various settings, a telephone book function, a mail function, and the like, and an input operation such as a numeric keypad for inputting a telephone number and characters such as mail. The key 14 and a determination operation key 15 for determining various operations, scrolling up and down, left and right, and the like.

  Each key constituting the operation unit 11 is assigned a predetermined function in accordance with the open / closed state of the operation unit side body 2 and the display unit side body 3 and the type of the activated application. In the cellular phone 1, when each key constituting the operation unit 11 is pressed by the user, an operation corresponding to the function assigned to each key is executed.

  The voice input unit 12 receives a voice uttered by the user of the mobile phone 1 during a call. The voice input unit 12 is disposed in the vicinity of the end (lower end) on the opposite side of the connection unit 4 in the longitudinal direction of the operation unit side body 2.

  The display unit side body 3 includes an audio output unit 31 and a display 34 (display unit) that forms a screen (display surface) that is exposed from the opening 3a of the display unit side body 3 and displays an image. The voice output unit 31 outputs the voice on the other side of the call. The audio output unit 31 is disposed on the end side opposite to the connection unit 4 in the longitudinal direction of the display unit side body 3.

  The display 34 includes a liquid crystal module 35 and a drive circuit 36. The liquid crystal module 35 is configured to exhibit a function of displaying an image via a display surface formed in the display unit side body 3. The liquid crystal module 35 is mounted inside the display unit side body 3. In the present embodiment, the liquid crystal module 35 includes a backlight 35a, a light guide plate 35b, a first polarizing plate 35c, an array substrate 35d, a liquid crystal panel 35e, a color filter 35f, as shown in FIG. A second polarizing plate 35g.

  The backlight 35a is configured to be able to emit a predetermined amount of light from the screen via the light guide plate 35b.

  The light guide plate 35b is disposed on the side of the backlight 35a, and is configured to be able to uniformly disperse light supplied from the backlight 35a over the entire screen.

  The first polarizing plate 35c is disposed in the upper layer of the light guide plate 35b, and is configured to allow only light irradiated from the lower layer to pass therethrough and reflect light from other directions to be shielded.

  The array substrate 35d is disposed in the upper layer of the first polarizing plate 35c, and includes a thin film transistor (TFT), so that pixels of an image displayed on the screen can be arbitrarily colored. The array substrate 35d is connected to the drive circuit 36 to control color development and the like.

  The liquid crystal panel 35e is formed by enclosing a liquid crystal material in a glass substrate material, and is disposed on the upper layer of the array substrate 35d. The liquid crystal panel 35e is configured to be able to deflect light that passes by applying a voltage to the liquid crystal material.

  The color filter 35f is arranged on the upper layer of the liquid crystal panel 35e, and is configured to allow passage of a specific wavelength range of visible light and block the specific wavelength range.

  The second polarizing plate 35g is disposed in the upper layer of the color filter 35f, and similarly to the second polarizing plate 35g, allows only the light irradiated from the lower layer to pass therethrough and shields the light from other directions by reflection or the like. Configured to be possible.

  The drive circuit 36 is connected to the array substrate 35d and the like of the liquid crystal module 35, and mainly controls screen display such as color development on the array substrate 35d. Further, the drive circuit 36 is configured to be able to reproduce an image stored in the storage unit 41 described later on the array substrate 35d. In the present embodiment, the display 34 is configured by the edge light method, but a direct type may be used.

  The mobile phone 1 configured as described above has a function of displaying a non-dazzling screen in accordance with ambient brightness without impairing visibility.

  Here, a configuration for exhibiting the functions as described above will be described with reference to FIG. FIG. 3 is a functional block diagram illustrating functions of the mobile phone 1 according to the present embodiment.

  As shown in FIG. 3, the mobile phone 1 includes a photometric sensor 37 (light sensor unit), an image processing unit 38, a brightness correction unit 39, a mode selection unit 40, a storage unit 41, a control unit 42, and the like. Have

  As shown in FIG. 1, the photometric sensor 37 is provided in the vicinity of the display 34 (in the present embodiment, in the vicinity of the left corner of the display 34) in the open state. The photometric sensor 37 measures ambient brightness as an external light amount.

  The image processing unit 38 processes an image displayed on the screen. The brightness correction unit 39 corrects the brightness of the image processed by the image processing unit 38.

  The mode selection unit 40 selects “normal mode (first mode)” and “gentle light amount mode (second mode)”. For the setting of “normal mode” and “gentle light amount mode”, for example, the current value (light amount) of the backlight corresponding to the measurement value of the photometric sensor 37 is stored in the storage unit 41 as a table. The “normal mode” is a mode in which the light amount is determined based on ambient brightness (external light amount) measured by the photometric sensor 37. The “friendly light amount mode” is a mode in which a light amount that is suppressed to be lower than the light amount in the “normal mode” is determined based on the ambient brightness (external light amount) measured by the photometric sensor 37. .

  The relationship between ambient brightness and light amount in the “normal mode” and “gentle light amount mode” will be described with reference to FIG. FIG. 4 is a diagram illustrating the relationship between the ambient brightness and the light amount of the backlight 35a in the “normal mode” and the “gentle light amount mode”. In FIG. 4, L1 is the current value of the backlight 35a in the “normal mode”, and L2 is the current value of the backlight 35a in the “gentle light amount mode”.

  The current value for determining the amount of light in the backlight 35a is determined based on the measured value measured by the photometric sensor 37, as shown in FIG. The measurement value that is the amount of external light measured by the photometric sensor 37 is replaced with a numerical value obtained by dividing the measurable range by, for example, 16 and is associated with the current value of the backlight 35a.

  In the “normal mode”, for example, a current value as a light amount of the backlight 35a is determined in consideration of human visual characteristics and power consumption under a predetermined brightness condition. Further, the current value of the backlight 35a is changed along with the brightness of the surroundings when the surroundings are bright (in the present embodiment, the current value is about 20 when the measured values of the photometric sensor 37 are near 15 to 12). To about 7 mA). Further, when the surroundings are dim, the predetermined light amount is maintained, and then changes more slowly than when the surroundings are bright (in this embodiment, the current measured by the photometric sensor 37 is about 12 to 3 near the current. The value is about 7 to about 3 mA). In addition, when the surroundings are dark, the screen cannot be seen without the illumination of the backlight 35a, so that the minimum current value is maintained (in this embodiment, the measured value of the photometric sensor 37 is around 3). In the vicinity of ˜1, the current value is about 3 mA).

Further, the relationship between the light amount in the “normal mode” and the “gentle light amount mode” and the correction of the brightness of the image will be described with reference to FIG. FIG. 5 is a diagram illustrating a relationship between the light amount and the brightness correction in the “gentle light amount mode”. In FIG. 5, L3 is the brightness of the image in the “friendly light amount mode”.
In the present embodiment, the brightness is set to be white at 100% and black at 0%. In a normal display, that is, in a state where the lightness is not corrected by the lightness correction unit 39, the lightness is set to 50%.

  In the “normal mode”, the brightness is not corrected even if the current value changes according to the ambient brightness. That is, the brightness is set to 50% regardless of the current value of the backlight 35a.

  On the other hand, in the “friendly light amount mode”, when the current value changes according to the ambient brightness, the brightness is corrected together with the change in the current value. In other words, in the “friendly light amount mode”, the lightness is determined so as to increase the lightness ratio as the current value is kept low.

  The storage unit 41 stores the light amount determined in the “normal mode” and the “gentle light amount mode” and the degree of correction of the brightness of the image as a table having a one-to-one correspondence with the measurement value of the photometric sensor. The storage unit 41 also has a frame memory function for storing an image to be displayed on the screen.

  When the “normal mode” is selected in the mode selection unit 40, the control unit 42 determines the light amount determined in the “normal mode” based on the ambient brightness measured by the photometric sensor 37. The backlight 35a is controlled so as to irradiate.

  In addition, when the “selective light amount mode” is selected in the mode selection unit 40, the control unit 42 is determined in the “friendly light amount mode” based on the ambient brightness measured by the photometric sensor 37. The backlight 35a is controlled so that it irradiates with the light quantity. Then, the control unit 42 controls the lightness correction unit 39 so as to correct the lightness level of the image according to the amount of light.

  The mobile phone 1 configured as described above is determined in the “friendly light amount mode” based on the ambient brightness measured by the optical sensor 37 when the “friendly light amount mode” is selected. The backlight 35a is controlled so that it irradiates with a light quantity. At this time, the mobile phone 1 controls the lightness correction unit 39 so as to correct the lightness of the image according to the amount of light.

Therefore, when the “gentle light amount mode” is selected, the mobile phone 1 keeps the light amount corresponding to the ambient brightness measured by the optical sensor 37 lower than the light amount determined in the “normal mode”. Therefore, the brightness of the screen by the amount of light can be reduced. As a result, screen glare can be reduced in the mobile phone 1. At this time, the mobile phone 1 can improve the difficulty of viewing the image due to the low light amount in order to reduce the light amount and correct the brightness of the image to be high. In addition, since the mobile phone 1 corrects only the lightness among the color attributes with respect to the correction of the image, it is possible to improve the difficulty of viewing the image with a small processing load.
In addition, when the “gentle light amount mode” is selected, the mobile phone 1 can reduce power consumption in the backlight 35a because the light amount is suppressed lower than that in the “normal mode”.

  The mobile phone 1 further includes a light amount changing unit 44. The light amount changing unit 44 can change the light amount determined in the “normal mode” and the “gentle light amount mode” step by step, and in the “gentle light amount mode”, the light amount is finer than the “normal mode”. It is configured to be changeable.

  Therefore, in the cellular phone 1, when the “friendly light amount mode” is selected, the user can change the light amount more finely than in the “normal mode”, so that the visual characteristics with respect to the glare of individual users are taken into consideration. Thus, the user can select an optimal screen display.

  Further, the mobile phone 1 further includes an application detection unit 43. The application detection unit 43 detects the attribute of the application to be started. In addition, when the “friendly light amount mode” is selected and the execution of the predetermined application is detected by the application detection unit 43, the control unit 42 is lower than the light amount determined in the “friendly light amount mode”. The suppressed light amount is determined.

  Further, the control unit 42 further irradiates the backlight 35a with a light amount suppressed to be lower than the light amount determined in the “friendly light amount mode” based on the ambient brightness measured by the photometric sensor 37. And the brightness correction unit 39 is controlled so as to correct the brightness level of the image according to the amount of light.

  When the “gentle light amount mode” is selected, the cellular phone 1 configured as described above detects the attribute of the application to be activated, and the light amount determined in the “gentle light amount mode” based on the activated application. Keep the amount of light even lower. This configuration can be applied to applications that are expected to be used for a long time, such as “one-segment partial reception service for mobile phones / mobile terminals” broadcasting, so-called one-segment broadcasting, for example, in the mobile phone 1. . When applied to such an application, since the brightness of the image is further reduced, it is possible to display an image that does not burden the eyes of the user, that is, the eyes of the user are not tired. In addition, since the mobile phone 1 is applied to an application that is expected to be used for a long time, it can achieve significant power saving.

  In the present embodiment, the mobile phone 1 sets the light amount determined in the “normal mode” and the “friendly light amount mode” as an upper limit value. That is, the light amount change by the light amount changing unit 44 is performed by lowering the light amount from the upper limit to a low light amount.

  Further, the light amount changing unit 44 can change the light amount based on the application when the application detecting unit 43 detects a specific application. Therefore, in the mobile phone 1, since the user can change the amount of light according to the application to be activated, an optimal screen display by the user himself / herself is considered in consideration of ease of eye fatigue of each user. Can be selected.

  The lightness correction unit 39 further measures the lightness of each pixel constituting the image, selects a lightness pixel lower than the predetermined lightness, and corrects the lightness level of the selected pixel according to the light amount. Therefore, the mobile phone 1 does not perform image correction on all the pixels in the displayed image, and performs image correction on pixels having a predetermined brightness or less, so that it is difficult to see with a small processing load. Can be improved.

Next, the operation of the mobile phone 1 will be described with reference to FIG. FIG. 6 is a flowchart showing the operation of the mobile phone according to the present invention.
As shown in FIG. 6, in step S <b> 1, the mobile phone 1 selects a mode by the mode selection unit 40 based on a user operation on the operation unit 11. If the “gentle light amount mode” is selected (Y), the process proceeds to step S2. If “normal mode” is selected (N), the process proceeds to step S3.

  In step S2, as shown in FIG. 7, the mobile phone 1 determines the function being used and sets the upper limit of the amount of light. FIG. 7 is a diagram for explaining display on the display when the “friendly light amount mode” is selected.

  That is, in this step, the mobile phone 1 is operated when a normal operation (a state where the application is not activated) is performed, or when an application such as e-mail that is difficult to be used for a long time is activated. Is set to perform the following processing. First, the mobile phone 1 is set by the control unit 42 so as to control the light amount (current value) of the backlight 35a based on the external light amount measured by the photometric sensor 37, as shown in FIG. . Next, the mobile phone 1 is set by the control unit 42 to control the brightness correction of the image by the brightness correction unit 39 based on the current value of the backlight 35a, as shown in FIG.

  On the other hand, when an application that is likely to be used continuously for a long time, such as watching 1Seg broadcasting, is running, the light intensity is controlled to be lower than the light intensity determined in the `` gentle light intensity mode '' determined based on the application. The screen display is set by correcting the brightness of the image based on the amount of light. At this time, the specific application is activated by detecting the attribute of the application to be activated by the application detection unit 43.

  At this time, in the mobile phone 1, the upper limit value of the light amount of the backlight 35a is set to a different value for each type of application, and therefore the light amount is changed by the light amount changing unit 44 in accordance with the usage form of the user. Can be changed low. That is, in the mobile phone 1, it is possible to select a light amount that is lower than the upper limit light amount determined by the application step by step for each application. Further, in the mobile phone 1, the light intensity level is finely set according to the application to be activated. In the present embodiment, as shown in FIG. 7, the light intensity level of an application for viewing a one-segment broadcast that is used for a long time is finely set. For example, in the case of a web browser application, if the light intensity is lower than that of an e-mail application and higher than that of a one-segment application, it is used more continuously than e-mail and is less likely to be used continuously than a TV. Along the way, it can be an eye-friendly control.

  In step S3, the “normal mode” is set by a user operation. That is, in the mobile phone 1 in which the “normal mode” is set, the control unit 42 sets the current value of the backlight 35 a based on the external light amount measured by the photometric sensor 37 as shown in FIG. Based on the external light quantity by the photometric sensor 37, the screen display is operated.

  In step S <b> 4, the mobile phone 1 for which the “friendly light amount mode” is set measures the external light amount. That is, the cellular phone 1 measures the ambient brightness by the photometric sensor 37, and proceeds to step S5. That is, in the mobile phone 1, the control unit 42 controls the light amount of the backlight 35a based on the external light amount measured by the photometric sensor 37 as shown in FIG.

  In step S5, the mobile phone 1 measures the ambient brightness (external light amount) with an optical sensor. If the external light amount is not changed (N), the process proceeds to step S6, and the external light amount is changed. In (Y), the process proceeds to step S7.

  In step S6, when there is a change in the image displayed on the screen (Y), the mobile phone 1 proceeds to step S8, and when there is no change in the image displayed on the screen (N), step S4 is performed. Proceed to

  In step S7, the mobile phone 1 adjusts the light amount of the backlight 35a based on the external light amount measured by the photometric sensor, and proceeds to step S8. Therefore, the mobile phone 1 controls the optimal light amount of the backlight 35a according to the external light amount under the “friendly light amount mode” in which the light amount of the backlight 35a is suppressed as compared with the “normal mode”.

  In step S8, the mobile phone 1 applies color tone correction to increase the brightness of the image, and proceeds to step S4. That is, in the mobile phone 1, the control unit 42 performs control so that the brightness of the image is corrected to be high by the brightness correction unit 39 based on the light amount (current value) of the backlight 35 a. At this time, as shown in FIG. 7, the mobile phone 1 does not consider the mode or the like, and the displayed image generated by the image processing unit 38 is based on the light amount determined in consideration of the mode and the application. Then, the image generated by correcting the brightness to be high is processed for display on the screen. Further, as shown in FIG. 7, the lightness correction unit 39 corrects the pixels whose lightness is below a certain value.

  Although the mobile phone 1 is configured to directly display the image after the change of the brightness when the image (display image) displayed on the screen is changed, the present invention is not limited to this. The mobile phone 1 only needs to be configured to reduce discomfort and difficulty in viewing due to the display image being switched to the user. When there is a change in the display image, the mobile phone 1 may be configured to display once with a light amount that is lower than the currently set light amount and then gradually change to the original light amount. . In addition, the mobile phone 1 may be configured so that, for example, the brightness of the image is corrected at a lower rate than the correction level after changing the display image, and gradually changed to the correction level after the change. In addition, although the mobile phone 1 has shown an example of the stepwise change of the light amount and the brightness correction of the image described above when the display image is changed, the present invention is not limited to this, and the display image is switched by combining them in combination. You may comprise.

  Therefore, the mobile phone 1 can perform screen display with reduced glare without impairing visibility.

  The preferred embodiment of the mobile phone 1 according to the present invention has been described above, but the mobile phone 1 according to the present invention can be implemented in various forms without being limited to the above-described embodiment.

  In the present embodiment, the mobile phone 1 is configured to correct the brightness of the image, but is not limited thereto. In the mobile phone 1, for example, it is only necessary to compensate for the difficulty in viewing the screen due to the low light amount of the backlight 35 a, and other color attributes such as the hue and color of the image are corrected, the hue of the image, You may comprise so that it may correct | amend combining a color or a brightness.

  Moreover, in this embodiment, although the mobile telephone 1 performed mode selection by a user's operation, it is not restricted to this. For example, the mobile phone 1 may be configured to automatically select the mode selection by determining the visual characteristics of the user from the profile registered in the address book or the like, the characteristics of the user's operation, and the like.

  Further, in the present embodiment, the mobile phone 1 is configured to operate the screen display with one table configured to correspond one-to-one to each value measured in the storage unit 41 by the optical sensor 37. However, it is not limited to this. Based on the measurement result by the photometric sensor 37, the light amount and the image correction degree may be calculated each time, and the screen display may be operated based on the calculation result.

  In the present embodiment, the mobile phone 1 sets the light amount determined in the “normal mode” and the “gentle light amount mode” as an upper limit, and the light amount change by the light amount change unit 44 is lowered from the upper limit to a lower light amount. However, the present invention is not limited to this. In the mobile phone 1, the light amount change by the light amount changing unit 44 may be configured to be increased or decreased with reference to the light amount determined in the “normal mode” and the “gentle light amount mode”. In addition, the mobile phone 1 is changed by the user's operation. However, the present invention is not limited to this. The mobile phone 1 may be configured to determine the visual characteristic and automatically change the same as in the mode selection. .

  In the present embodiment, more preferably, the mobile phone 1 directly displays the amount of light determined by the mode or the like when displaying an image after switching in order to reduce the burden on the user's eyes due to image changes. Instead, it may be configured to gradually shift to a target light amount. In this case, the mobile phone 1 may be configured to perform image correction and gradually display an image instead of or in addition to the light amount change described above.

  In the present embodiment, the present invention is applied to a mobile phone that is an example of a mobile electronic device, but the present invention is not limited to this. For example, you may apply to PHS (Personal Handyphone System), PDA (Personal Digital Assistant), a portable navigation apparatus, a notebook personal computer, a display apparatus etc.

1 Mobile phone (mobile electronic device)
34 Display (display part)
35b Backlight (irradiation part)
37 Photometric sensor (optical sensor)
38 Image processing unit 39 Lightness correction unit 40 Mode selection unit 42 Control unit 43 Application detection unit 44 Light amount change unit

Claims (5)

A transmissive display unit having a display surface;
An irradiation unit that irradiates the display surface directly or indirectly from the back surface with a predetermined amount of light;
An optical sensor for measuring ambient brightness;
An image processing unit for processing an image displayed on the display surface;
A brightness correction unit that corrects the brightness of the image processed by the image processing unit;
A first mode in which the amount of light is determined based on ambient brightness measured by the optical sensor unit, and an amount of light in the first mode based on ambient brightness measured by the optical sensor unit. A mode selection unit that selects a second mode in which the light amount suppressed to a lower level is determined;
When the second mode is selected in the mode selection unit, irradiation is performed with the light amount determined in the second mode based on ambient brightness measured by the optical sensor unit. A portable electronic device having a control unit that controls the lightness correction unit so as to control the irradiation unit and correct the degree of lightness of the image according to the amount of light. A light amount changing unit capable of stepwise changing the light amount determined in the first mode and the second mode,
2. The portable electronic device according to claim 1, wherein the light amount changing unit can change the light amount more finely in the second mode than in the first mode. An application detection unit that detects an attribute of the application to be started;
In the case where the second mode is selected and the control unit detects the execution of a predetermined application by the application detection unit, the light amount is suppressed to be lower than the light amount determined in the second mode. Is determined, and based on the ambient brightness measured by the optical sensor unit, the irradiation unit is controlled to irradiate with a light amount suppressed lower than the light amount determined in the second mode, The portable electronic device according to claim 2, wherein the brightness correction unit is controlled to correct the brightness level of the image according to the amount of light.   The portable electronic device according to claim 3, wherein the light amount changing unit can change the light amount according to the type of application detected by the application detecting unit.   The lightness correction unit measures the lightness of each pixel constituting the image, selects a pixel having a lightness lower than a predetermined lightness, and corrects the lightness of the selected pixel in accordance with the amount of light. 4. The portable electronic device according to 4.

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