JP4207252B2 - Display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device capable of displaying an image by arranging a plurality of light emitting elements in a dot shape, and a method for arranging the light emitting elements .
[0002]
[Prior art]
For example, as a display device for a large screen, a display device that displays an image using a light emitting diode (hereinafter referred to as LED (Light Emitting Diode)) as a light emitting element has been developed.
FIG. 8 shows the LEDs mounted on the mounting surface of the display panel of the display device.
On the mounting surface 1021 of the display unit 1020, for example, LEDs indicated by ◯ are arranged in a horizontal inline arrangement. These LEDs correspond to the colors R (red), G (green), and B (blue), respectively, as shown in the circles, and each of the four LEDs of each RGB color is a set. The pixel 1022 is thus configured. When the display screen of the display device is formed by the display unit 1020, a plurality of display units 1020 are combined so that the number of pixels corresponds to the resolution of the display device. FIG. 9 shows an example of the luminous intensity distribution of the LED.
[0003]
In the display device in FIG. 8, LEDs are connected in series for each color, and are lit by applying the same signal and modulating. Of course, the LEDs of each color can be connected in parallel, but in this case, four times the constant current source is required.
[0004]
[Problems to be solved by the invention]
By the way, such a display unit 1020 is recently used in, for example, a large-screen display device for outdoor advertising such as a wall surface of a building. However, the uniformity of color and brightness is poor compared to a display device using, for example, a CRT (Cathode Ray Tude) or a discharge tube, and it is desired to improve the uniformity of color and brightness for further market expansion. ing. Thus, there has been a tendency to adjust the luminous intensity (intensity) for each pixel even in display devices using LEDs.
[0005]
However, as shown in FIG. 9, the luminous intensity of the LEDs varies widely, the minimum luminous intensity is about 1 / 1.4 of the average value, and the luminous intensity adjustment needs to be adjusted to the minimum luminous intensity value. Therefore, when the uniformity of color and luminous intensity (luminance) is improved, there is a problem that the luminance is reduced to 1 / 1.4.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a display device that can solve the above-described problems and can improve the uniformity of a display screen without significantly reducing luminance.
[0006]
[Means for achieving the object]
To solve the above problems and achieve an object of the present invention, the display device of the present invention, a display device in which a plurality of same modulated by the light emitting elements constituting pixels arranged in a matrix are arranged in a dot shape The light emitting elements that emit light at a light intensity between the first light intensity and the second light intensity that is higher than the first light intensity are classified as the first group, the second light intensity, A light-emitting element that emits light at a light intensity between a third light intensity that is higher than the light intensity is classified as a second group, and the pixel includes at least a first group and a second group, and the light emission of the first group The element emits light at the first luminous intensity, and the second group of light emitting elements emits light at the second luminous intensity.
[0007]
As described above, in the display device of the present invention, a plurality of light-emitting elements that are modulated in the same manner that form pixels arranged in a matrix are arranged in the form of dots. It is classified into several groups according to the height. That is, the first group of light-emitting elements that emit light at a first luminous intensity (low) or higher and a second luminous intensity (middle) or lower is the first group, and the second luminous intensity (middle) or higher and the third luminous intensity (high) or lower. The light-emitting elements that emit light at the luminous intensity are classified as the second group. Each pixel includes at least a light emitting element included in the first group and a light emitting element included in the second group. The light emitting elements in the first group have a first luminous intensity (low). ) And the second group of light emitting elements emit light at the second luminous intensity (medium). Thereby, the uniformity of a display screen can be made favorable, without reducing luminance too much.
[0008]
In a preferred embodiment of the present invention, the light-emitting elements that are modulated in the same manner are a light-emitting element that emits red (R), a light-emitting element that emits green (G), and a light-emitting element that emits blue (B). is there. As a result, it is possible to perform color display with good uniformity of the screen without significantly reducing the luminance.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
The embodiment described below is a preferred specific example of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these forms.
[0013]
FIG. 1 shows a preferred embodiment of the display device of the present invention.
A display device 10 shown in FIG. 1 includes a case (housing) 11, and the case 11 includes a mounting substrate 12 for mounting a light emitting diode (LED), for example. On the mounting substrate 12, red (R), green (G), and blue (B) LEDs are arranged in, for example, a horizontal in-line arrangement pattern as shown in FIG. The case 11 includes a control device for controlling the LEDs arranged in this way.
[0014]
In each pixel 20 of the display device 10, each color per pixel 20 is composed of two LEDs. That is, one pixel 20 has a total of six LEDs: red LEDs 30R1 and 30R2, green LEDs 30G1 and 30G2, and blue LEDs 30B1 and 30B2.
[0015]
In the display device 10, the case 11 is attached to the substrate 12, and a plurality of pixels 20 are arranged in a matrix, and the LEDs are arranged in dots in the pixel 20. The green LEDs 30G1 and 30G2 are electrically connected in series, the red LEDs 30R1 and 30R2 are also connected in series, and the blue LEDs 30B1 and 30B2 are also connected in series, and are electrically connected to the control device described above.
[0016]
In each one pixel 20 of FIG. 1, the red LEDs 30R1 and 30R2 are the same modulated light emitting elements, and the green LEDs 30G1 and 30G2 are also the same modulated light emitting elements. The blue (B) LEDs 30B1 and 30B2 are light-emitting elements that are further modulated in the same manner. Each of the pixels 20 is devised as follows in order to improve the luminous intensity of each pixel without reducing the luminance so much and improving the uniformity of the screen.
[0017]
FIG. 2 shows an example of the luminous intensity distribution having the minimum luminous intensity (lowest luminous intensity), maximum luminous intensity (maximum luminous intensity), and the center of luminous luminous intensity (average luminous intensity). When the minimum luminous intensity in FIG. 2 is 1, the average luminous intensity that is the center of the luminous luminous intensity is 1.4, and the maximum luminous intensity is 1.8.
The red LEDs 30R1 and 30R2 in FIG. 1 are divided into two groups (divided into integer multiples), for example, a group A having a minimum luminous intensity of 1 to a maximum luminous intensity of 1.4 and a group B having a minimum luminous intensity of 1.4 to a maximum luminous intensity of 1.8. . That is, the A group and the B group divide the luminous intensity distribution equally into two with the average luminous intensity as the center. As an example, the red LED 30R1 is selected as an arbitrary one from the luminous intensity of the A group, and the other red LED 30R2 selects an arbitrary one from the luminous intensity of the B group. Adopted. These red LEDs 30R1 and 30R2 are electrically connected in series.
[0018]
Similarly, any one of the green LEDs 30G1 in FIG. 1 is selected from the group A in FIG. 2, and any one of the green LEDs 30G2 in the group B is selected electrically. Connected in series. The blue LED 30B1 is selected from any one in the group A, and the blue LED 30B2 is selected in the group B and connected in series.
In this way, the selected LEDs 30R1, 30R2, 30G1, 30G2, 30B1, and 30B2 constitute one pixel 20. As a result, the minimum light intensity of one pixel 20 can be regarded as 1.2, which is an average value of the minimum light intensity 1 of the A group and the minimum light intensity 1.4 of the B group in FIG.
By doing so, it is possible to realize the display device 20 with good screen uniformity without reducing luminance by improving the luminous intensity of one pixel 20.
[0019]
Reference is now made to FIGS. 3 and 4 show another embodiment of the display device of the present invention.
A display device 40 shown in FIG. 3 includes a case 11 and a mounting substrate 42. A plurality of one pixel 50 are arranged on the mounting substrate 42, and a plurality of LEDs are arranged in a dot shape on one pixel 50. This one pixel 50 has four green LEDs 60G1, 60G2, 60G3, 60G4, four red LEDs 60R1, 60R2, 60R3, 60R4, and four blue LEDs 60B1, 60B2, 60B3, 60B4.
[0020]
The green LEDs 60G1 to 60G4 are electrically connected in series. Similarly, the four red LEDs 60R1 to 60R4 are also connected in series, and the four blue LED LEDs 60B1 to 60B4 are also connected in series.
[0021]
In order to improve the pixel luminous intensity of one pixel 50 of the display device 40 of FIG. 3 and to improve the uniformity of the screen without significantly reducing the luminance, the following measures are taken.
FIG. 4 shows an example of the luminous intensity distribution of the LEDs of the display device 40 of FIG. In FIG. 4, unlike the case of FIG. 2, it is further subdivided, A1 group in the range of minimum luminous intensity 1 to maximum luminous intensity 1.2, A2 group of minimum luminous intensity 1.2 to maximum luminous intensity 1.4, The B2 group in the region of minimum luminous intensity 1.4 to maximum luminous intensity 1.6 and the B1 group of minimum luminous intensity 1.6 to maximum luminous intensity 1.8 are divided into four divisions.
For example, the green LED 60G1 of one pixel 50 is an arbitrary one of the A1 group, the LED 60B2 is an arbitrary one of the B1 group, and the LED 60G3 is an arbitrary one of the A2 group, and 60G4 is the B2 group Adopt any one of and combine. Such a combination is also extracted and combined in the red LEDs 60R1 to 60R4 and the blue LEDs 60B1 to 60B4.
As a result, the average value of the minimum luminous intensity of the A1 group and the minimum luminous intensity 1.6 of the B1 group in FIG. 4 is 1.3, and the average of the minimum luminous intensity of the second group 1.2 and the minimum luminous intensity of the B group 1.4. The value is also 1.3, and the minimum luminous intensity (total luminous intensity) in one pixel 50 in FIG.
[0022]
Although not shown, in the luminous intensity distribution diagram of FIG. 2 or FIG. 4, when performing 6 divisions, the luminous intensity per pixel is 1.333, and when performing 8 divisions, the luminous intensity distribution per pixel The luminous intensity is 1.35, which is close to the luminous intensity of the pixel of 1.4 when the minimum luminous intensity and the maximum luminous intensity are combined, and then one is combined so as to be inside one.
[0023]
Next, FIG. 5 and FIG. 6 show still another embodiment of the present invention.
A mounting plate 72 is provided on the case 11 of the display device 70 of FIG. A plurality of pixels 90 are arranged on the mounting plate 72. In one pixel 90, a plurality of LEDs are arranged in a dot shape. One pixel 90 includes three green LEDs 100G1, 100G2, and 100G3, red LEDs 100R1, 100R2, and 100R3, and blue LEDs 100B1, 100B2, and 100B3.
The three green LEDs 100G1, 100G2, and 100G3 are regularly connected in series. Similarly, the red LEDs 100R1, 100R2, and 100R3 are also connected in series, and the blue LEDs 100B1, 100B2, and 100B3 are also connected in series.
[0024]
FIG. 6 shows an example in which the light intensity distribution of the LED is divided into three. In FIG. 6, a group A having a minimum luminous intensity 1 to a maximum luminous intensity 1.27, a group C having a minimum luminous intensity 1.27 to a maximum luminous intensity 1.53, and a group B having a minimum luminous intensity 1.53 to a maximum luminous intensity 1.8. It is divided into three.
For example, the green LED 100G1 of one pixel 90 in FIG. 5 is selected as any one in group A, 100G2 is selected as any one in group B, and LED 100G3 is selected as group C. Combined as any one of. Such processing is performed not only for the green LED but also for the red LED and the blue LED, and one pixel 90 is constituted by such selected LEDs.
As a result, since the average value of the minimum luminous intensity 1 of the A group and the minimum luminous intensity 1.53 of the B group is 1.27, and the minimum luminous intensity of the C group is 1.27, the luminous intensity (total luminous intensity) of one pixel 90 is It can be regarded as 1.27.
If the luminous intensity distribution is close to the normal distribution, only the C group remains. In this case, one pixel may be formed by any three groups in the C group.
[0025]
FIG. 7 shows an example in which each LED of one pixel 90 of the display device 70 as shown in FIG. 5 is selected by being divided into three by another method.
The luminous intensity width in FIG. 7 is not uniform, but the number of LEDs belonging to each group is the same. That is, the number of LEDs belonging to the A group, the C group, and the B group is the same.
[0026]
In FIG. 7, a group A having a minimum luminous intensity 1 to a maximum luminous intensity 1.35, a group C having a minimum luminous intensity 1.35 to a maximum luminous intensity 1.45, and a group B having a minimum luminous intensity 1.45 to a maximum luminous intensity 1.8. It is divided into three. For example, the green LED 100G1 in FIG. 5 is selected as any one in Group A, LED 100G2 is selected as any one in Group C, and LED 100G3 is selected as any one in Group B. To be combined. By performing such processing together with the red LED and the blue LED, one pixel 90 is configured.
As a result, since the average value of the minimum luminous intensity 1 of the A group, the minimum luminous intensity 1.35 of the C group, and the minimum luminous intensity 1.45 of the B group is 1.27, the luminous intensity (total luminous intensity) of one pixel 90 is obtained. Can be regarded as 1.27.
[0027]
As described above, according to the present invention, when a plurality of LEDs are used per pixel, by combining LEDs that are substantially symmetrical with respect to the center of the luminous intensity distribution, the luminance at the time of display on the entire display device is not reduced. A display device with good screen uniformity can be realized.
In addition, by dividing the luminous intensity distribution evenly by an integer multiple of the number of each LED per pixel, a display device with good screen uniformity can be realized without significantly reducing luminance. It can be used without waste and requires relatively little time for combination.
[0028]
Conventionally, in a display in which LEDs with large variations in brightness (luminance) are arranged, the luminous intensity of all LEDs is adjusted to the minimum luminous intensity of the LEDs. However, in the present invention, when a plurality of LEDs are used in one pixel, the light intensity can be designed with an average light intensity by using a combination of light intensity symmetrical with respect to the variation center. The total price can be reduced to 1 / 1.4.
[0029]
The present invention is not limited to the above-described embodiment, and other types of light-emitting elements can be employed besides LEDs. The electrical connection of the LEDs may be a parallel connection as well as a serial connection to the control device.
[0030]
【The invention's effect】
As described above, according to the present invention, the uniformity of the display screen can be improved without significantly reducing the luminance.
[Brief description of the drawings]
FIG. 1 is a front view showing a preferred embodiment of a display device of the present invention.
FIG. 2 is a luminous intensity distribution diagram showing an example of LED selection in one pixel of the display device of FIG. 1;
FIG. 3 is a front view showing another embodiment of the display device of the present invention.
4 is a luminous intensity distribution diagram for selecting an LED in one pixel of the display device of FIG. 2;
FIG. 5 is a front view showing still another embodiment of the display device of the present invention.
6 is a luminous intensity distribution diagram for selecting an LED of one pixel of the display device of FIG. 5;
7 is a luminous intensity distribution diagram for selecting an LED of one pixel of the display device of FIG. 5;
FIG. 8 shows a conventional display device.
FIG. 9 is a luminous intensity distribution diagram of LEDs of a conventional display device.
[Explanation of symbols]
10 ... display device, 20 ... one pixel, 30G1, 30G2, 30G3 ... green LED, 30R1, 30R2, 30R3 ... red LED, 30B1, 30B2, 30B3 ... blue LED .

Claims (2)

In the display device in which a plurality of same modulated by the light emitting elements constituting pixels arranged in a matrix are arranged in a dot shape,
Classifying light emitting elements that emit light at a light intensity between a first light intensity and a second light intensity that is higher than the first light intensity as a first group,
Classifying light emitting elements that emit light at a light intensity between the second light intensity and a third light intensity that is higher than the second light intensity as a second group;
The pixels include at least the first group and the second group;
The display device, wherein the first group of light emitting elements emits light at the first luminous intensity, and the second group of light emitting elements emits light at the second luminous intensity.   2. The pixel according to claim 1, wherein the pixel includes a light emitting element that emits red (R), a light emitting element that emits green (G), and a light emitting element that emits blue (B). Display device.

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