JP2588492Y2 - Display device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device in which a plurality of light emitting diodes for emitting red, green, and blue light are respectively provided to perform color display on a display device.

[0002]

2. Description of the Related Art Conventionally, when performing full color display,
Light sources of three primary colors of red, green, and blue are required, and light sources using light emitting diodes for the purpose of reducing power consumption are known. A display device using this light-emitting diode has provided a plurality of light-emitting diodes for emitting red, green, and blue light, respectively, and controls the lighting of each light-emitting diode according to display data, thereby obtaining a full-color display.

[0003]

However, in a display device using three-color light-emitting diodes, the brightness of red and green light-emitting diodes is sufficient, but the brightness of blue light-emitting diodes is comparable. There was a problem that bright and clear color display could not be obtained. On the other hand, if the driving current for driving the blue light emitting diode is increased, the brightness reaches the same level as other light emitting colors, but the heat generated from the blue light emitting diode and the driving for driving the blue light emitting diode to light up. Due to the heat generated by the IC, the inside of the display falls into an abnormal temperature, causing failure of the electric parts. SUMMARY OF THE INVENTION The present invention has been made to address such a problem, and has as its object to suppress a rise in temperature of an electric component provided in a display and to prevent a failure of the electric component.

[0004]

In order to solve the above problems, the present invention provides a display having a plurality of light emitting diodes for emitting red, green and blue light, respectively, and an image supply for outputting RGB signals. Means, a temperature sensor for detecting the temperature in the display, and RGB input from the image supply means when the temperature detected by the temperature sensor is lower than a predetermined temperature.
Image signal switching means for outputting a signal, and when the temperature is higher than a predetermined temperature, outputting the remaining RG signals from which the B signal has been deleted from the RGB signals inputted from the image supply means; and RGB signals outputted from the image signal switching means. Display processing means for driving each light-emitting diode arranged on the display based on a signal or an RG signal.

[0005]

The temperature inside the display is detected, and if the detected temperature is lower than the predetermined temperature, gradation display is performed using light emitting diodes of three colors. If the detected temperature is higher than the predetermined temperature, the blue light emitting diode is turned on. The remaining two light-emitting diodes are used for gradation display to prevent abnormal overheating of the display.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of the entire configuration of the display device,
The display device includes a plurality of light-emitting diodes of three colors for displaying a color image, a personal computer (hereinafter abbreviated as a personal computer) 2 for sequentially outputting display data according to a display schedule created in advance, and the personal computer. A data processing unit 3 for converting the display data output from the display unit 2 into data for display on the display 1, and each light emission provided on the display 1 based on the data supplied from the data processing unit 3. It is formed by a display drive unit 4 for controlling lighting / non-lighting of the diode.

FIG. 2 is a block diagram showing the internal structure of a display 1, a personal computer 2, a data processor 3 and a display driver 4. The display 1 includes light emitting diodes for emitting red, green and blue light, respectively. .., 5 capable of displaying one character by arranging them in a matrix of i × j dots in vertical and horizontal directions as one dot.
5,..., 5 are arranged in a matrix of M × N vertically and horizontally to form a display screen. A temperature sensor 6 such as a thermistor is provided inside the display 1 to detect the temperature inside the display 1.

In the personal computer 2, a display 8 and a keyboard 9 are connected to the personal computer body 7, and a graphic display control board 10, a hard disk interface board 11 and an I / O board 12 are set in expansion slots of the personal computer body 1, respectively. ing. Hard disk interface board 1
A plurality of display software including display data and an operation sequence, a display schedule including a group of display software to be displayed during a display period,
Each of the control programs is stored. The display software and display schedule are created in advance by another personal computer and registered in the hard disk 13. Based on the control program, the personal computer 2 sequentially reads out display software according to a display schedule, develops the display software on the VRAM of the graphic display control board 10 as an actual display screen, and has the same analog RGB signals and horizontal / vertical synchronization as the data displayed on the display It is output in the form of a signal.

The data processing unit 3 converts the analog RGB signals output from the personal computer 2 into A / D conversion circuits 14r,
A digital conversion unit 14 for converting the digital RGB signals output from the digital conversion unit 14 into digital RGB signals via the unit panels 5, 5,.
M-number of row memory 15 _1, 15 to the row direction as a unit
- _2, ..., a storage unit 15 for storing the 15-n, the digital converter 14 row unit memory 15 ₁ digital RGB signals outputted from, 15 _2, ..., address for writing to 15-n , and each row unit memory 15 _1, 15 _2, ..., 15
an address generating circuit 16 respectively generates addresses for reading the digital RGB signals stored in -n, each row unit memory _{15- 1, 15- 2, ...,} m pieces of data read from the 15-n To m gradation data conversion circuits 17
- _1, 17 _2, ..., consisting of the gradation conversion unit 17 for converting the gradation data through the 17-n.

[0010] Analog RGB output from the personal computer 2
Signals are converted into 4-bit parallel digital RGB signals through the digital converter 14, each row unit memory 15 ₁ in the order in which they are outputted from the digital converter 14, 15 _2, ..., 1
Written to 5-n. Row memory 15 _1, 15 _2,
, 15-n, the data is read from the right end to the left end in the row direction of each of the unit panels 5, 5, ..., 5 and the 4-bit parallel data is output to the gradation conversion unit 17. This read operation is continuously performed 16 times. In the gradation conversion unit 17, once the data of the lower first bit of the input data is 1 according to the weight of the input data, once, 2
When the data of the bit is 1, the parallel data is output twice, when the data of the third bit is 1, 4 times, and when the data of the 4 bit is 1, the parallel data is output 8 times.
The divided light and dark display is performed.

Reference numeral 18 denotes an image signal switching circuit which is interposed between signal lines connected to the personal computer 2 and the A / D conversion circuit 14b, and is provided with an analog B signal by a control signal supplied from the personal computer main body 7 via the I / O board 12. Is switched on / off. Reference numeral 19 denotes an A / D conversion circuit which receives the output of the temperature sensor 6 and converts it into digital data.
It is output to the O board 12.

The display drive unit 4 turns on / off each light emitting diode.
Driving circuit 4 including a driving IC group for controlling non-lighting 4-
_{11, 4- 12, ..., 4} -mn each unit panels 5,5, ..., 5
Each unit panel 5, 5, ..., 5
, 4-m ₁ , 4-m ₂ ,..., 4-
mn are connected in series, M serial data output from the gradation conversion unit 17 is shifted, data is held by a latch signal, and lighting / non-lighting of each light emitting diode is controlled by static driving. By the way, the driving current for driving each light emitting diode is about 3 mA for red and about 1 for green.
5 mA and 40 mA for blue. When all the light emitting diodes are fully lit, the driving I
The heat generation of C and blue light emitting diodes is much larger than that of other light emitting diodes.

Next, the processing operation based on the temperature detection of the display will be described with reference to the flowchart of FIG. The personal computer 2 generates a temperature detection interrupt signal at predetermined time intervals,
When an interrupt signal is generated, A / D conversion circuit 19 to capture the temperature of the thermistor 6 through (1), compares the detected temperature T the first predetermined temperature T ₁ and (2). In this judgment, when the detected temperature T is lower than the first set temperature T ₁ , a conduction signal is supplied from the personal computer 7 to the image signal switching circuit 18 via the I / O board 12, and three colors of red, green and blue are provided. (3).

On the other hand, if the detected temperature T is higher than the first set temperature T ₁ , the detected temperature T is compared with the second set temperature T ₂ higher than the first set temperature T _1. (4). In this determination, the detected temperature T is set to the second
For lower than the set temperature T ₂ the display data to be displayed to determine whether character data or graphic data (5). In this judgment, if the display data is character data, a shutoff signal is supplied from the personal computer body 7 to the image signal switching circuit 18 via the I / O board 12, and gradation display using two colors of red and green is performed (6). If the display data is graphic data, the personal computer 7 sends the I / O board 12
To the image signal switching circuit 18 via the
A gradation display using three colors of green and blue is performed (7).

On the other hand, if the detected temperature T is higher than the second set temperature T ₂ in the judgment of step (4), the detected temperature T is compared with the third set temperature T ₃ higher than the second set temperature T _2. (8). In this determination, the detected temperature T becomes the third
If the temperature is lower than the set temperature T ₃ , I /
A shut-off signal is supplied to the image signal switching circuit 18 via the O board 12, and a two-color gradation display of red and green is performed (9).
Further, the detected temperature T is if it is determined that the third higher than the set temperature T ₃ abnormal temperature to stop the display stops the output of the analog RGB signals (10).

In this way, when the temperature in the display 1 reaches a high temperature, the lighting control of the light emitting diode for emitting blue light is stopped to suppress a rise in the temperature of the electric component due to the lighting of the blue light emitting diode, thereby preventing the failure of the electric component. Can be prevented.

[0017]

[Effect of the Invention] The present invention is configured as described above,
A display in which a plurality of light emitting diodes respectively emitting green and blue light are arranged; an image supply means for outputting RGB signals; a temperature sensor for detecting a temperature in the display; and a temperature detected by the temperature sensor being a predetermined temperature When the temperature is lower, the RGB signal input from the image supply unit is output. When the temperature is higher than the predetermined temperature, the RGB signal input from the image supply unit is output.
Image signal switching means for outputting the remaining RG signal from which the B signal has been deleted from the signals, and lighting driving of each light emitting diode arranged on the display based on the RGB signal or the RG signal output from the image signal switching means With such a display processing means, the heat generation of the electric component is suppressed, and the failure of the electric component can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration block diagram of a display device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the internal configuration of a display 1, a personal computer 2, a data processing unit 3, and a display drive unit 4 in the display device.

FIG. 3 is a flowchart showing the operation of the display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display 2 Personal computer 3 Data conversion part 4 Display drive part 6 Temperature sensor

Continuation of the front page (56) References JP-A-3-220590 (JP, A) JP-A-3-58087 (JP, A) JP-A-62-275588 (JP, A) JP-A-6-175600 (JP, A) , A) Japanese Utility Model Application No. 2-68140 (JP, U) Japanese Utility Model Application Utility Model No. 1-136995 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) G09G 3/00-3/38

Claims (1)

(57) [Scope of request for utility model registration] 1. A display in which a plurality of light emitting diodes for emitting red, green, and blue light are arranged, an image supply unit for outputting RGB signals, a temperature sensor for detecting a temperature in the display, and the temperature sensor. If the detected temperature is lower than the predetermined temperature, the RGB signal input from the image supply unit is output. If the detected temperature is higher than the predetermined temperature, the remaining RG signals obtained by deleting the B signal from the RGB signals input from the image supply unit. an image signal switching means for outputting, and further comprising a display processing means for lighting drive the light emitting diodes arranged in the display unit based on the output RGB signals or RG signal from the image signal switching means Display device.