JP2006078748A - Portable apparatus and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable apparatus for reducing consumption current, while securing the overall brightness, without causing luminance uneveness with respect to various displays, such as characters and images, and to provide a display device. <P>SOLUTION: The portable apparatus comprises an LED display panel matrix-arranging a plurality of a light emitting diodes projected toward the outside on a plane; and a display control part for controlling to display the light-emitting diode on the LED display panel on display data, in which light emission of the light-emitting diode adjacent to the light emitting diodes lowers the gradation of each light emitting diode in response to a light quantity leaked on a light-emitting point of each light-emitting diode, on the basis of a display pattern displayed on the LED display panel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device and a portable device such as a mobile phone provided with the display device, and more particularly, a portable device that secures luminance when the display device is turned on and reduces power consumption of the display device. The present invention relates to a device and a display device.

  As a conventional technique, there is a display device that suppresses power consumption by slowing the lighting duty of these LEDs and lowering the lighting brightness when the number of LEDs that are lit in a specified area is a predetermined number or more (for example, Patent Document 1).

JP-A-4-157495 (page 3-4, FIG. 1)

  The display device of Patent Document 1 has a problem that brightness unevenness occurs at the boundary between blocks because the brightness of the display device is determined for each block.

  The present invention has been made to solve the above-described problems. For various displays such as characters and images, the current consumption is ensured without causing uneven brightness and ensuring the overall brightness. An object of the present invention is to obtain a portable device and a display device that can be reduced.

  The portable device and the display device according to the present invention are each based on an LED display panel in which a plurality of light emitting diodes projecting toward the outside are arranged in a matrix on a plane, and a display pattern to be displayed on the LED display panel. The light emission of the LED display panel based on display data in which the gradation of each light emitting diode is lowered according to the amount of light emitted from the light emitting diode adjacent to the light emitting diode leaks to the light emitting point of each light emitting diode. And a display control unit that controls the display of the diode.

  In the portable device and the display device according to the present invention, the light emission of the light emitting diode adjacent to each light emitting diode leaks to the light emitting point of each light emitting diode based on the display pattern displayed on the LED display panel. Since the display of the light emitting diodes of the LED display panel is controlled based on the display data in which the gradation of each of the light emitting diodes is lowered, luminance unevenness occurs in various displays such as characters and images. In addition, there is an effect that current consumption can be reduced while ensuring the overall luminance.

Embodiment 1 FIG.
FIG. 1 is an external view of a two-fold type mobile phone as an example of a portable device according to the present invention, and FIG. 1 (a) is a perspective view as seen from the front side in a state where the two-fold type mobile phone is opened. 1 (b) is a perspective view seen from the back side. In the figure, the operation side housing 1 has an operation portion in which a plurality of operation keys 2 are arranged, and one end side is connected to one end of the display side case 4 by a hinge 3. On the other end side of the operation side housing 1, a microphone 5 used by the user for a call is provided. On the other hand, a main display section 6 for displaying characters and images is provided on the front side of the display side housing 4 as shown in FIG. The main display unit 6 is a liquid crystal display (LCD). A receiver 7 that outputs the voice of the other party is provided on the other end of the display-side housing 4. Further, as shown in FIG. 1B, an LED display panel 9 in which a plurality of light emitting diodes (LEDs) 8 are arranged in a matrix is provided on the back side of the display side housing 4. The LED display panel 9 is mounted on a display window formed on the back surface of the display-side housing 4 and has 153 LEDs 8 arranged in m rows × n columns, in the example shown, 17 rows × 9 columns. The LEDs 8 are mounted at a pitch of 3.2 mm, and the size of the display portion of the LED display panel 9 is about 2.4 inches (53.9 mm × 28.3 mm). Therefore, the LED display panel 9 occupies substantially the entire area of the back surface of the display-side housing 4 and can display a high luminance on a relatively large screen.

FIG. 2 is a block diagram of the two-fold type mobile phone according to the first embodiment. In the figure, an antenna 10 for wireless communication receives radio waves received from a call partner and inputs them to the radio unit 11. The radio unit 11 amplifies and frequency-converts the input signal and inputs it to the baseband IC 12. The baseband IC 12 as the main control unit controls the entire mobile phone, and operates according to a program stored in the memory unit 13 as the storage unit. The memory unit 13 stores various data and data to be processed by the baseband IC 12 in addition to a program for operating the baseband IC 12.
When there is an incoming call, the baseband IC 12 rings the speaker 15 via the sound unit 14 to notify the user of the incoming call. When the user responds to the incoming call, the baseband IC 12 connects the terminal of the other party to the line and connects the microphone. 5 and a call using the receiver 7 are enabled. The user's voice is taken into the mobile phone through the microphone 5 and transmitted via the acoustic unit 14, the baseband IC 12, the radio unit 11, and the antenna 10.
The operation unit 16 includes operation keys 2. An RTC (real time clock) 17 outputs accurate time information. The power supply control unit 18 supplies power generated by the battery 19 to each unit, supplies power supplied from the charging terminal 20 to the battery 19, and charges the battery 19. The battery 19 is accommodated in the operation side housing 1. The infrared communication means 21 performs near field data communication, and the camera 22 is built in the mobile phone.

The LED display panel 9 includes a control microcomputer 23, an X-direction control driver 24, a Y-direction control driver 25, and LEDs 8 arranged in a matrix in 17 rows and 9 columns. The control microcomputer 23, the X direction control driver 24, and the Y direction control driver 25 function as a display control unit that controls the display of the LED 8.
The display can display a pattern such as a figure or a pattern. For example, the display can be performed when a mobile phone receives a call or during a call. The pattern displayed on the LED display panel 9 can be scrolled in the left-right direction and the up-down direction, blinked, and displayed with gradation. Therefore, since the display with high brightness and high impact can be performed, the user can notice the incoming call even when the mobile phone is received at a position away from the user.

  Such a display pattern is stored in the memory unit 13. When an event such as an incoming call occurs and the baseband IC 12 detects this, the display pattern data is read from the memory unit 13 and transferred to the control microcomputer 23. To do. The control microcomputer 23 that has received the display pattern data drives the X-direction control driver 24 and the Y-direction control driver 25 based on the data, and displays patterns such as figures and patterns on the LEDs 8 arranged in a matrix.

  FIG. 3 is an explanatory view showing the display control principle of the two-fold mobile phone according to the first embodiment using a part (3 rows × 3 columns) of the LED display panel 9, and FIG. It is a figure which shows the gradation characteristic of LED8 which concerns on this invention.

  3A is a perspective view of a part of the LED display panel 9 (3 rows × 3 columns). In this embodiment, the LEDs 8 are arranged on the substrate 26 in a matrix with a pitch interval of 3.2 mm. The distance between the LED 8 and the projection surface 27 parallel to the substrate 26 is 1.6 mm. (B) is a simplified view of a part (3 rows × 3 columns) of the LED display panel 9 as viewed from the projection plane 27 side. A, a, b, c, d, e, f, g, h are each The light emission points on the projection surface 27 corresponding to the LED 8, and the areas A ′, a ′, b ′, c ′, d ′, e ′, f ′, g ′, h ′ are the light emission points A, a, b, The areas illuminated brightly by the LEDs 8 respectively corresponding to c, d, e, f, g, and h are shown. (C) is a simplified view of a part of the LED display panel 9 as viewed from the side, and shows the positional relationship between the light emission points A, g, and h.

  FIG. 4 is a diagram showing the luminance / gradation characteristics of the LED 8 according to the first embodiment. The LED 8 is controlled at 36 gradations from the gradation 35 having the maximum luminance to the gradation 0 having the minimum luminance. Is shown.

  Here, when the LED 8 corresponding to the light emission point g adjacent to the light emission point A and the light emission point h adjacent to the right lower side of the light emission point A is turned on, from the LED 8 corresponding to the light emission point g and the light emission point h. The amount of light leaking to the light emission point A will be described.

The luminance at the light emission point g when the LED 8 corresponding to the light emission point g is lit at the gradation 35 which is the maximum luminance is about 820 cd / m ² from FIG. Therefore, the luminance at the light emission point A at a distance of 1.6√5 mm from the LED 8 corresponding to the light emission point g is
820 ÷ (1.6√5 ÷ 1.6) ² = 164 cd / m ²
It becomes. However, the LED 8 has directivity, and the amount of attenuation increases rapidly as the distance from the center point of the light emission point g increases, that is, as the distance from the area g ′ increases. Here, for convenience, when the attenuation is calculated as 1/5, the amount of light leaking to the light emission point A when the LED 8 corresponding to the light emission point g is lit at the maximum brightness is
164 ÷ 5 = 32.8 cd / m ²
It becomes. That is, for each LED 8, the amount of light that leaks to the light emitting point corresponding to the LED 8 adjacent vertically and horizontally is 32.8 cd / m ² .

Similarly, when the LED 8 corresponding to the light emission point h is lit at the gradation 35 which is the maximum luminance, the luminance at the light emission point A at a distance of 1.6 × 3 mm from the LED 8 corresponding to the light emission point h is
820 ÷ (1.6 × 3 ÷ 1.6) ² ≈91.1 cd / m ²
It becomes. When the attenuation is calculated as 1/5, the amount of light leaking to the light emission point A when the LED 8 corresponding to the light emission point h is lit is:
91.1 ÷ 5 ≒ 18.2 cd / m ²
It becomes. That is, for each LED 8, the amount of light leaking to the light emitting point corresponding to the diagonally adjacent LED 8 is 18.2 cd / m ² .

Therefore, when the LED 8 corresponding to the light emission point g and the LED 8 corresponding to the light emission point h are lit at the gradation 35, the luminance at the light emission point A is the same even if the corresponding LED 8 is not lit.
32.8 + 18.2 = 51.0 cd / m ²
Thus, the brightness for two gradations can be secured from FIG.
Furthermore, if all the eight LEDs 8 adjacent to the LED 8 corresponding to the light emission point A are lit at the gradation 35, the luminance at the light emission point A is the same even if the corresponding LED 8 is not lit.
32.8 × 4 + 18.2 × 4 = 204.0 cd / m ²
Accordingly, it is possible to secure the brightness for nine gradations from FIG.
In this case, the LED 8 corresponding to the light emission point A is
820-204.0 = 616 cd / m ²
If the light is lit at a luminance of 520 cd / m ² , the maximum luminance of 35 gradations can be secured.

If a current of 20 mA is required to light one LED 8 with a luminance of 820 cd / m ² (gradation 35), a current consumption for lighting with a luminance of 204.0 cd / m ² (204.0 × 20 ) ÷ 820 ≒ 4.98mA
Can be reduced.

  Next, a display pattern conversion process using this characteristic will be described.

  5A is a diagram showing a display pattern of the LEDs 8 in a matrix arrangement of m rows × n columns stored in the memory unit 13, that is, a configuration of the luminance D required for each LED 8. (B) is a figure which shows the brightness | luminance structure in the display pattern which added the area | region of brightness | luminance "0" to the outer peripheral part of the display pattern of (a) virtually, (c) is the floor in this Embodiment 1. It is a figure which shows the structure of the brightness | luminance N in the display pattern after performing a tone conversion process.

Here, the luminance at the light emission point when the LED 8 is turned on at the maximum luminance gradation 35 is about 820 cd / m ² , and the amount of light leaking from the LED 8 adjacent to the upper, lower, left and right to the central light emission point is 32.8 cd / m ² ,
32.8 ÷ 820 = 0.04
As a result of this calculation, 0.04 times the amount of light leaks from the LEDs 8 that are adjacent vertically and horizontally. In other words, if the central light emission point is (χ, γ) and the luminance of the LEDs 8 adjacent to the upper, lower, left and right is D, the amount of light leaking from the upper, lower, left and right adjacent LEDs 8 to the central light emission point is
0.04 × ( _{Dχ−1, γ} + _{Dχ, γ + 1} + _{Dχ + 1, γ} + _{Dχ, γ−1} )
It can be expressed by the following formula.
Similarly, the amount of light leaking from the diagonally adjacent LED 8 to the central light emitting point is 18.2 cd / m ² ,
18.2 ÷ 820 ≒ 0.02
As a result of the calculation, 0.02 times the amount of light leaks from the diagonally adjacent LEDs 8. That is, the amount of light leaking from the diagonally adjacent LED 8 to the central light emitting point is
0.02 × ( _{Dχ-1, γ} + _{Dχ, γ + 1} + _{Dχ + 1, γ} + _{Dχ, γ-1} )
It can be expressed by the following formula.

Therefore, the amount of light leaking from the LED 8 adjacent to the light emitting point corresponding to each LED 8 is:
0.04 × ( _{Dχ−1, γ} + _{Dχ, γ + 1} + _{Dχ + 1, γ} + _{Dχ, γ−1} )
+ 0.02 × ( _{Dχ-1, γ-1} + _{Dχ-1, γ + 1} + _{Dχ + 1, γ-1} + _{Dχ + 1, γ + 1} )
Therefore, in order to secure the luminance D _{χ, γ} required at the central light emission point (χ, γ), the lighting luminance required in the LED 8 corresponding to the central light emission point is
N _{χ, γ} = D _{χ, γ}
− {0.04 × ( _{Dχ−1, γ} + _{Dχ, γ + 1} + _{Dχ + 1, γ} + _{Dχ, γ−1} )
+ 0.02 × ( _{Dχ−1, γ−1} + _{Dχ−1, γ + 1} + _{Dχ + 1, γ−1} + _{Dχ + 1, γ + 1} )}
This can be expressed by the conversion formula A.

However, since the luminance D in the adjacent LED 8 is actually lit with the converted luminance N, the amount of light leaking from the adjacent LED 8 is less than the calculation of the conversion formula. Therefore, using the correction coefficient α satisfying 0 <α <1, the conversion equation A is corrected as follows to obtain the conversion equation B.
N _{χ, γ} = D _{χ, γ}
− {0.04 × α × ( _{Dχ−1, γ} + _{Dχ, γ + 1} + _{Dχ + 1, γ} + _{Dχ, γ−1} )
+ 0.02 * [alpha] * (D [ _{chi] -1, [gamma] -1} + D [ _{chi] -1, [gamma] +1)} + D [ _{chi] +1, [gamma] -1} + D [ _{chi] +1, [gamma] +1} )}.

  When the baseband IC 12 stores the display pattern data of FIG. 5A in the memory unit 13, a display in which an area of luminance “0” is virtually added to the outer periphery of the display pattern of FIG. FIG. 5B as a pattern is generated. Thereafter, the display pattern data of FIG. 5C is generated from the display pattern data of FIG. 5B using the conversion formula B, and stored in the memory unit 13.

  When displaying a display pattern such as a figure or a pattern on the LED display panel 9, the baseband IC 12 reads the display pattern data shown in FIG. 5C from the memory unit 13 and transfers it to the control microcomputer 23. The control microcomputer 23 that has received the display pattern data drives the X-direction control driver 24 and the Y-direction control driver 25 based on the data, and displays patterns such as figures and patterns on the LEDs 8 arranged in a matrix.

  As described above, since the light amount leaking from the LED 8 adjacent to each LED 8 is used based on the display pattern data such as a figure or a pattern to be displayed, the gradation of the LED 8 is lowered and the light is turned on. Current consumption can be reduced while ensuring the overall luminance.

In this embodiment, the case where the LEDs 8 on the LED display panel 9 are simultaneously turned on (static lighting control) has been described. However, the present invention can also be applied to the case of row scanning or column scanning (dynamic lighting control). In this case, since only the amount of light leaking from the LED 8 adjacent to the same row can be used, the conversion formula is
N _{χ, γ} = D _{χ, γ}
−0.04 × α × (Dχ _{, γ + 1} + Dχ _{, γ−1} )
It becomes.

  In this embodiment, the display pattern data shown in FIG. 5A is converted into the display pattern data shown in FIG. 5C when stored in the memory unit 13. When displaying on the LED display panel 9, the baseband IC 12 reads the display pattern data of FIG. 5A from the memory unit 13 and converts it to the display pattern data of FIG. 5C using the above conversion formula. However, it may be transferred to the control microcomputer 23.

  The portable device according to the present invention can be used in the fields of portable wireless terminals such as cellular phones, portable information terminals and the like. The display device according to the present invention can also be used in the field of an electric bulletin board installed on a bullet train, a bank, or the like for display by a number of light emitting diodes arranged in a matrix.

1 is an external view of a two-fold type mobile phone as a mobile device according to the present invention. FIG. 1 is a block configuration diagram of a two-fold type mobile phone according to Embodiment 1. FIG. It is a figure which shows the display control principle of the two-fold type mobile telephone which concerns on this Embodiment 1. FIG. It is a figure which shows the brightness | luminance and gradation characteristic of LED8 which concerns on this Embodiment 1. FIG. It is a figure which shows the brightness | luminance structure of the display pattern of the LED display panel 9 concerning this Embodiment 1. FIG.

Explanation of symbols

8 LED
9 LED display panel 12 Baseband IC
13 Memory Unit 23 Control Microcomputer 24 X Direction Control Driver 25 Y Direction Control Driver

Claims (8)

An LED display panel in which a plurality of light emitting diodes projecting toward the outside are arranged in a matrix on a plane;
Based on the display pattern displayed on the LED display panel, the gradation of each light emitting diode is adjusted according to the amount of light emitted from the light emitting diode adjacent to each light emitting diode to the light emitting point of each light emitting diode. A portable device comprising: a display control unit that controls display of the light emitting diode of the LED display panel based on display data that is lowered. An LED display panel in which a plurality of light emitting diodes projecting toward the outside are arranged in a matrix on a plane;
A display control unit for controlling the display of the light emitting diode of the LED display panel based on the input display data;
Based on the display pattern displayed on the LED display panel, the gradation of each light emitting diode is adjusted according to the amount of light emitted from the light emitting diode adjacent to each light emitting diode to the light emitting point of each light emitting diode. A portable device comprising: a main control unit that generates display data to be lowered and outputs the generated display data to the display control unit. An LED display panel in which a plurality of light emitting diodes projecting toward the outside are arranged in a matrix on a plane;
A display control unit for controlling the display of the light emitting diode of the LED display panel based on the input display data;
Based on the display pattern to be displayed on the LED display panel, display data for lowering the gradation of the light emitting diode is generated according to the gradation of the light emitting diode adjacent to the light emitting diode, and the generated display data is displayed on the display. A portable device comprising a main control unit that outputs to a control unit. A storage unit for storing display data;
The main control unit stores the generated display data in the storage unit, and outputs the display data stored in the storage unit to the display control unit when displaying the light emitting diode of the LED display panel. The portable device according to claim 2 or 3. A storage unit for storing the display pattern;
4. The portable device according to claim 2, wherein the main control unit generates display data based on the display pattern stored in the storage unit when displaying the light emitting diode of the LED display panel. . An LED display panel in which a plurality of light emitting diodes projecting toward the outside are arranged in a matrix on a plane;
Based on the display pattern displayed on the LED display panel, the gradation of each light emitting diode is adjusted according to the amount of light emitted from the light emitting diode adjacent to each light emitting diode to the light emitting point of each light emitting diode. A display device comprising: a display control unit that controls display of the light emitting diodes of the LED display panel based on display data that is lowered. An LED display panel in which a plurality of light emitting diodes projecting toward the outside are arranged in a matrix on a plane;
A display control unit for controlling the display of the light emitting diode of the LED display panel based on the input display data;
Based on the display pattern displayed on the LED display panel, the gradation of each light emitting diode is adjusted according to the amount of light emitted from the light emitting diode adjacent to each light emitting diode to the light emitting point of each light emitting diode. A display device comprising: a main control unit that generates display data to be lowered and outputs the generated display data to the display control unit. An LED display panel in which a plurality of light emitting diodes projecting toward the outside are arranged in a matrix on a plane;
A display control unit for controlling the display of the light emitting diode of the LED display panel based on the input display data;
Based on the display pattern to be displayed on the LED display panel, display data for lowering the gradation of the light emitting diode is generated according to the gradation of the light emitting diode adjacent to the light emitting diode, and the generated display data is displayed on the display. A display device comprising: a main control unit that outputs to the control unit.

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