JP2002091385A - Illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a function for enhancing visibility such as contrast and a function for saving power by performing the illumination of an LED(light emitting diode) unit corresponding to respective pixels of an LCD(liquid crystal display). SOLUTION: In this illuminator, the illumination of the LCD is constituted of LEDs. One piece of the LED is arranged for every three pixels of R, G, and B of the LCD and one piece of a white LED equivalent to the portion of the resolution of the LCD is arranged by being made to correspond to the three pieces of R, G, and B of the LCD. The driving of the LEDs is performed with information to be received from an LCD controller. When the black of the LCD is to be displayed, corresponding LEDs are all turned OFF. Thus, the illuminator can enhance the visibility by raising the contrast and also has large power saving effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device mounted on an electronic device. In particular, the present invention relates to a portable device having a relatively high-resolution LCD display device mainly driven by a battery.

[0002]

2. Description of the Related Art Heretofore, as a lighting device, a lighting technology using a cold cathode tube and a light guide plate has been almost established, and recently, a device having high luminance and high efficiency has been realized. In particular, portable devices are required to be used in, for example, a dark environment, an environment in which sunlight is too bright, or a severely cold environment such as a low temperature of -20 ° C. Under these circumstances, there is a face that the cold cathode fluorescent lamp illumination cannot sufficiently cope with. Attempting to produce high luminance makes it difficult to control at low luminance, and the light is turned off. Also, it does not turn on in an environment of -20 ° C. In addition, there is a problem that it is very dark even if it is turned on. Currently, white LEDs are being actively developed as next-generation lighting replacing the cold cathode tubes. For example, JP-A-04-1595
No. 19 liquid crystal display device with LED illumination and a method for manufacturing the same are known. This is to arrange LED chips on the back surface of the LCD and to realize uniform illumination on the concave reflecting surface. However, this requires that the light source be
D, and did not sufficiently exhibit the characteristics of the LED.

[0003]

The following describes an example of a cold cathode tube. Since the cold-cathode tube emits light from the surface, the entire surface is turned on and off,
And brightness adjustment, but it is difficult to partially turn on and off the screen and adjust the brightness. In addition, since the response time is slow, it is not suitable for short-time turning on / off. That is, there is a problem that it is not possible to adjust lighting and turning off and brightness in a microscopic time and a microscopic space, and it is difficult to reduce power consumption.

[0004] In view of the above, the present invention makes it possible to turn on and off and adjust the brightness in a microscopic time and microscopic space,
It is an object of the present invention to provide a lighting device that achieves improvement in contrast and power saving.

[0005]

According to a first aspect of the present invention, there is provided an LCD display device comprising an LCD, an LCD control circuit for controlling the LCD display device, L comprising an LED for individually irradiating a light transmitting portion of each pixel of the LCD with a microlens for each pixel and the LED drive wiring
ED lighting device and LED for driving the LED lighting device
And a control circuit.

[0006] The invention according to claim 2 of the present invention provides:
An LCD display device constituted by an LCD, an LCD control circuit for controlling the LCD display device, an LED for individually irradiating a light transmitting portion of each pixel of the LCD with light for each pixel, and the LED drive wiring. LE
D lighting device, an LED control circuit for driving the LED lighting device, and an LCD non-display period detecting means for extracting information of a non-display period for controlling the LCD display device from the LCD control circuit and instructing the LCD control circuit. The LED lighting device is turned off only during the non-display period. During the non-display period, the LED of the LED lighting device is also turned off, and the power supplied to the LED is reduced, so that an improvement in power saving can be realized.

[0007] The invention according to claim 3 of the present invention provides:
An LCD display device constituted by an LCD, an LCD control circuit for controlling the LCD display device, an LED for individually irradiating a light transmitting portion of each pixel of the LCD with light for each pixel, and the LED drive wiring. LE
A D lighting device, an LED control circuit for driving the LED lighting device, and black detection means for extracting information for displaying black on the LCD display device from the LCD control circuit and instructing the LCD control circuit. The LED of the LED lighting device corresponding to the portion is turned off. LED corresponding to the black part of the LCD
By turning off the LED of the lighting device, power can be reduced. In addition, since there is no illumination of the black portion, the contrast between the black portion and the color display portion can be improved.

The invention according to claim 4 of the present invention provides:
An LCD display device constituted by an LCD, an LCD control circuit for controlling the LCD display device, an LED for individually irradiating a light transmitting portion of each pixel of the LCD with light for each pixel, and the LED drive wiring. LE
D lighting device, an LED control circuit for driving the LED lighting device, and means for grasping position information of the window screen accessed by the input device among the window screens provided to the LCD display device by the LCD control circuit, L of the LED lighting device corresponding to the window portion
This is characterized by increasing the luminance of the ED. By increasing the brightness of the LED in the accessed window portion, it is possible to increase the contrast as compared with the window other than the window.

The invention according to claim 5 of the present invention provides:
An LCD display device constituted by an LCD, an LCD control circuit for controlling the LCD display device, an LED for individually irradiating a light transmitting portion of each pixel of the LCD with light for each pixel, and the LED drive wiring. LE
A D lighting device, an LED control circuit for driving the LED lighting device, and means for grasping position information of a window screen which is not accessed from the input device for a certain period of time in a window screen provided to the LCD display device by the LCD control circuit. The brightness of the LED of the LED lighting device corresponding to the window portion not accessed is reduced stepwise. As a result, the illumination of the LED is always maintained only in the accessed window portion to improve the contrast, and the window that is not accessed is
It becomes possible to reduce the power consumption of the lighting of the LED in the ow portion.

The invention according to claim 6 of the present invention provides:
6. The illumination device according to claim 1, wherein an illuminance detection circuit for detecting illuminance of a surrounding environment, and when the surroundings are bright based on information of the illuminance detection circuit, light is emitted from the LED illumination device to control the LCD display device. Command input / output control means for issuing an instruction to make the passed illuminance brighter than the surrounding illuminance and, when the surroundings are dark, emitting light from the LED lighting device to make the illuminance passed through the LCD display device darker than the surrounding illuminance. is there. Thereby, an improvement in contrast can be realized.

The invention according to claim 7 of the present invention provides:
The lighting device according to any one of claims 1 to 6 is used for a personal computer.

The invention according to claim 8 of the present invention provides:
The lighting device according to any one of claims 1 to 6 is used for a digital still camera.

[0013] The invention according to claim 9 of the present invention provides:
The lighting device according to any one of claims 1 to 6 is used for a camera movie.

Further, the invention according to claim 10 of the present invention uses the lighting device of claims 1 to 6 for a portable telephone.

The invention according to claim 11 of the present invention uses the lighting device according to any one of claims 1 to 6 for an information portable terminal.

[0016]

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS.

FIG. 1 is a diagram showing a circuit configuration of a lighting device according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing a pixel structure and an illumination method. As shown in FIG. 1, the overall configuration is such that the LCD control circuit 4 connected to the CPU 16 and the LC
It can be composed of a D display device 1, an LED control circuit 3, and an LED lighting device 2. R1 (5), G1 (6), B1 (7), R2 (5)
There are a pixel 11 and a pixel 12 that transmit the three primary colors of (8), G2 (9) and B2 (10). An LED array 201 is arranged immediately below each pixel. LED
The illumination device 2 is a white LED array in which all the LEDs and the wiring for the LED drive are collectively generated on a silicon substrate. Above the LEDs 13 and 14, there is a microlens 15 which is formed so that the light emitted from each LED shines far beyond each pixel of the LCD by 0.01 mm. This microlens 15 transmits the light of each LED to each LCD.
Accurately converge to a size 0.01 mm larger than the square shape of the pixel. The LCD control circuit 4 generates display data of the LCD display device 1 according to an instruction from the CPU 16. The LED control circuit 3 controls turning on / off of each LED and adjusting brightness.

Next, an operation principle according to the first embodiment of the present invention will be described. Display data 4 from LCD control circuit 4
s is sent to the LCD display device 1 and R1 of the pixel 11 is
(5), G1 (6), B1 (7), R2 of pixel 12
(8), G2 (9), B2 (10),...
The LED control circuit 3 sends a pulse drive signal 3s to the LED lighting device 2. The LEDs 13 and 14 corresponding to each pixel of the LCD display device 1 supply an appropriate luminance to the LCD display device 1 by the pulse drive signal 3s.
At this time, each LED 13, LE
The light emitted from D14 is converged into a regular square and illuminates each of the pixels 11 and 12 of the LCD display device 1. At this time, as shown in FIG. 2, the light emitted from the LED 13 is 0.01 mm from the pixel 11 of the LCD display device 1.
It is condensed so that it becomes larger, R1 (5), G1 (6),
Even light reaches B1 (7).

With this configuration, it is possible to prevent light from leaking into the adjacent pixels 12 and the like,
The extra light falling on the LED 13
The amount of light that actually reaches the human eye among the light emitted from the light source can be increased.

In the above example, the LCD control circuit 4 has C
PU16 is connected and controlled, but not necessarily CPU
It is not necessary to use a dedicated hardware such as a wired logic circuit.

(Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described with reference to FIG.

FIG. 3 is a drawing showing a circuit configuration of a lighting device according to Embodiment 2 of the present invention. CPU 16 and L
CD control circuit 4, LED control circuit 3, and LCD display device 1.
And the LED lighting device 2 are the same as those in the first embodiment, and the description is omitted. The LCD control circuit 4 is connected to the LCD non-display period detection circuit 18, and the LCD non-display period detection circuit 18 is connected to the LED control circuit 3.

Next, the operation principle of the second embodiment of the present invention will be described. The screen non-display period signal 4d detected by the LCD control circuit 4 carries information for turning off the LCD display screen. The LCD non-display period detecting circuit 18 detects this signal and sends a signal 18d for turning off the LED to the LED control circuit 3. Thus, when the LCD is not displayed, the LED is also turned off at the same time, and the power consumption during that period is also reduced.

Generally, when switching the LCD screen, the LCD is turned off so that unnecessary dust is not seen by the operator.
I do. Conventionally, at that time, the lighting is continued to be turned on, and only the LCD is displayed in black by the OFF signal. In this embodiment, since the LED is turned off when the LCD is turned off, the power consumption of the illumination can be reduced for a short time.

(Embodiment 3) Hereinafter, Embodiment 3 of the present invention will be described with reference to FIG.

FIG. 4 is a drawing showing a circuit configuration of a lighting device according to Embodiment 3 of the present invention. In the third embodiment, the LCD black display pixel detection circuit 1 is used as black detection means instead of the LCD non-display period detection circuit 18 of the second embodiment.
9 is different.

Next, the operation principle of the third embodiment of the present invention will be described. Generally, in the LCD control circuit 4, the LCD
The RGB data at the display pixel (x, y) is (0,
At (0, 0), black is displayed at the pixel (x, y) in the LCD display device 1. (X, y) means LC
The pixel exists at the x-th position from the upper left to the right and the y-th position from the upper left in the D display device 1. The LCD black display pixel detection circuit 19 detects the pixels (x,
When the data of (y) is (0, 0, 0), it is detected as black, and a signal 19d for turning off the LED of the pixel (x, y) is given to the LED control circuit 3. The LED control circuit 3 controls the LED to turn off the LED of the pixel (x, y).
Drive array 201.

As a feature of this embodiment, in the case of the conventional surface-emitting type cold-cathode tube illumination, the illumination is turned on even with a black display pixel, and the LCD has an electronic shutter with a polarizing film. Light leakage of about 1 cd / m ² occurred. Therefore, the contrast obtained by dividing the luminance of the white display section by the luminance of the black display section is, for example, 150 cd /
It was 150 when m ² . In this embodiment, the LED of the black pixel (xb, yb) is turned off and the illumination itself is not performed, and the adjacent pixel (xb + 1, yb)
0.1c of light leaked from LED and micro lens
d / m ² or less, white color is 150 cd / m ²
In this case, the contrast is as high as 1500. In other words, the white crispness becomes very good. Further, since the LED in the black display portion is turned off, power can be saved accordingly.

(Embodiment 4) Hereinafter, Embodiment 4 of the present invention will be described with reference to FIGS. 5, 6, 7, 8, and 9. FIG.

FIG. 5 is a diagram showing a circuit configuration of a lighting device according to Embodiment 4 of the present invention. The present embodiment is different from the third embodiment in that a window detection circuit 20 is used instead of the LCD black display pixel detection circuit 19 and a mouse click detection circuit 21 is further provided. For example, as shown in FIG. 6, two window A and window
owB is displayed on the LCD display device 1. The upper left start point of windowA is (xA, yA), and the lower right end point is (xA + a1, yA + a2).
Similarly, the start point at the upper left of windowB is (xB, yB), and the end point at the lower right is (xB + b1, yB + b2).
The starting point at the upper left of the entire background screen is (x0, y0), and the ending point at the lower right is (x0 + O1, y0 + O2).

Next, the operation principle of the present embodiment will be described. The window detection circuit 20 detects a plurality of existing w
The position information of the window is received from the CPU 16.
In this example, the start point (xA, yA) and the lower right end point (xA + a1, yA + a2) of windowA are detected, and windowA is detected.
The starting point (xB, yB) at the upper left of wB and the ending point (xB +
b1, yB + b2) are detected, and the upper left start point (x0, y0) and the lower right end point (x0 + O1, y0 +
O2) is detected. As shown in FIG. 6, window A is used as an LCD display screen before accessing by clicking the mouse.
May be on the back of windowB, the brightness of windowA may be bright, and the brightness of windowB may be darker. At this time, windowB is placed on windowA.
Is given priority to the dark luminance of windowB.

Next, FIG. 7 shows a diagram when an arbitrary part of windowA is clicked with a mouse. In a general OS, after clicking, windowA is displayed above windowB. At this time, the mouse click detection circuit 21 detects that the mouse has clicked an arbitrary point in windowA, and notifies the CPU 16 of the click. CPU
16 informs the window detection circuit 20 of the upper and lower data of the window. The window detection circuit 20 is LC
The data 4d is reacquired from the D control circuit 4, and the LED control circuit 3 increases the brightness of the LED corresponding to the window A portion. In this way, the brightness of the window clicked with the mouse becomes highest. Other windows
And the brightness of the window of the background is lower than this. In this way, the brightness of only the window portion where the mouse is operated is increased to make it easier to see.

FIG. 8 shows an LCD after a certain time has passed after clicking.
It shows a display screen. The CPU 16 has a timer function for managing time, and if a mouse click is not input for a certain period of time, the number of clicks is small.
Is given to the window detection circuit 20. The darkening speed can be set in the CPU 16 in advance. In FIG. 8, windowA has been clicked three times and has been clicked in the closest past.
owB was clicked twice in the past, and the window of the background
When There have been clicked once in the past, windowA the most bright 150cd / m ^2, windowB next darker 100cd / m ^2, is the most dark window of background 7
0 cd / m ² . In addition, when it is set to be darker after 3 minutes from the CPU, windowB is set after 3 minutes.
Has a luminance of 70 cd / m ² and a background window of 40 cd.
/ M ² and gradually becomes darker. If it is set to turn off after 10 minutes from the CPU, window A
Will continue at 150 cd / m ² , but all lighting in window B and the window portion of the background will be extinguished.

When the CPU 16 is set so that all the screens disappear after 20 minutes, the window A
Disappears after 20 minutes, and the entire screen goes out and disappears.

In the above example, w is not accessed.
Although the brightness of the window portion is reduced stepwise, the number of steps may be two. That is, the luminance of the window part that is not accessed may be erased.

Next, in FIG.
Since there is a part that is overwritten by dowB and cannot be seen, drag it with the mouse to change windowA to win.
When the screen is separated from dowB, the brightness of the entire area of windowA of the screen displayed on the LCD display device 1 increases as shown in FIG. That is, in this case, the window being accessed
The operation of increasing the brightness of the w portion is performed continuously while the window moves, and the brightness of the corresponding LED also changes as the window A moves. As a result, due to the window position movement, the portion whose brightness has been increased also moves following the window position movement. This is shown in FIG.

The feature of this embodiment is that only windows that are frequently used are illuminated and windows that are not used are illuminated.
For ow, electric power is not used as much as possible to save power.

Embodiment 5 Hereinafter, Embodiment 5 of the present invention will be described with reference to FIG.

FIG. 10 is a diagram showing a circuit configuration of a lighting device according to Embodiment 5 of the present invention. In this embodiment, an ambient illuminance detection circuit 22 is used instead of the mouse click detection circuit 21 of the fourth embodiment. The CPU 16 is used as a command input / output control unit. Next, the operation principle in the present embodiment will be described. Ambient illuminance detection circuit 2
2 measures the surrounding illuminance and sends data to the CPU 16.
In the bright sun, the CPU 16 increases the illuminance emitted from the LED illumination device 2 and passed through the LCD display device 1 until it becomes higher than the surrounding illuminance.

Conversely, when the surroundings are dark, the CPU 16 also reduces the illuminance emitted from the LED lighting device 2 and passed through the LCD display device 1 until the illuminance becomes lower than the surrounding illuminance.
An instruction is given to the second detection circuit 20.

As a result, it is possible to improve visibility and save power in consideration of the surrounding environment.

The lighting apparatus described in the first to fifth embodiments can be used for a personal computer, a digital still camera, a camera movie, a mobile phone, and a personal digital assistant. Note that the mobile phone may be a PHS phone. Further, the portable information terminal may be a car navigation system terminal, a wearable PC, or a wristwatch with a communication function.

It is very effective to use the illuminating device of the present invention, which requires both high contrast and operates on battery power as described above, and achieves both improvement in contrast and power saving.

[0044]

As described above, according to the present invention, the LCD
By performing illumination in LED units corresponding to each pixel, a function of improving visibility such as contrast and a power saving function can be realized. By using the lighting device of the present invention for a small portable device or the like, the driving time of a battery can be dramatically improved as compared with the case where a conventional lighting device is used.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circuit configuration of a lighting device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing an internal structure of the lighting device according to Embodiment 1 of the present invention.

FIG. 3 is a diagram showing a circuit configuration of a lighting device according to Embodiment 2 of the present invention.

FIG. 4 is a diagram showing a circuit configuration of a lighting device according to Embodiment 3 of the present invention.

FIG. 5 is a diagram showing a circuit configuration of a lighting device according to Embodiment 4 of the present invention.

FIG. 6 illustrates an LC of a lighting device according to Embodiment 4 of the present invention.
Diagram showing D screen display

FIG. 7 illustrates an LC of a lighting device according to Embodiment 4 of the present invention.
Diagram showing D screen display

FIG. 8 illustrates an LC of a lighting device according to Embodiment 4 of the present invention.
Diagram showing D screen display

FIG. 9 illustrates an LC of a lighting device according to Embodiment 4 of the present invention.
Diagram showing D screen display

FIG. 10 is a diagram showing a circuit configuration of a lighting device according to Embodiment 5 of the present invention.

[Explanation of symbols]

 Reference Signs List 1 LCD display device 2 LED lighting device 3 LED control circuit 4 LCD control circuit 5 LCD red display R1 6 LCD green display G1 7 LCD blue display B1 8 LCD red display R2 9 LCD green display G2 10 LCD blue Display B2 11 LCD pixel 1 12 LCD pixel 2 13 LED1 that illuminates LCD pixel 1 14 LED2 that illuminates LCD pixel 15 LED microlens that condenses LED light into a square 16 CPU 17 Black stripe (non-display) 18) LCD non-display period detection circuit 19 LCD black display pixel detection circuit 20 window detection circuit 21 mouse click detection circuit 22 ambient illuminance detection circuit 201 LED array

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/20 612 G09G 3/20 642Z 5G435 642 680H 5K027 680 3/32 A 3/32 H01L 33/00 L H01L 33/00 H04M 1/00 Z H04M 1/00 1/725 1/725 1/725 G02F 1/1335 530 F term (reference) 2H091 FA45Z GA11 GA12 LA17 LA30 2H093 NC50 NC55 ND04 ND39 5C006 AF69 BB11 BF15 BF45 EA01 EC02 FA47 FA54 5C080 AA10 BB05 CC03 DD01 DD26 EE29 EE30 JJ01 JJ02 JJ06 5F041 AA14 AA24 BB34 EE11 FF11 5G435 AA00 AA02 BB12 BB15 CC09 CC12 EE26 EE30 FF13 GG02 GG23 GG26 5K027 AA11 BB01 BB17 CC08

Claims (11)

[Claims] 1. An LCD display device comprising an LCD, an LCD control circuit for controlling the LCD display device, and a micro lens for individually irradiating light to a light transmitting portion of each pixel of the LCD for each pixel. LED and L
An LED lighting device comprising wiring for an ED drive;
An illumination device including an LED control circuit for driving the ED illumination device. 2. An LCD display device comprising an LCD, an LCD control circuit for controlling the LCD display device, and an LED for individually irradiating light to a light transmitting portion of each pixel of the LCD for each pixel. An LED illuminating device comprising an LED drive wiring, an LED control circuit for driving the LED illuminating device, and information on a non-display period for controlling the LCD display device extracted from the LCD control circuit.
LCD non-display period detecting means for instructing the control circuit, and the LED lighting device is turned off only during the non-display period.
A lighting device characterized by: 3. An LCD display device comprising an LCD, an LCD control circuit for controlling the LCD display device, an LED for individually irradiating light to a light transmitting portion of each pixel of the LCD for each pixel, and An LED lighting device comprising wiring for an LED drive; an LED control circuit for driving the LED lighting device; and information for displaying black on an LCD display device from the LCD control circuit.
A black detecting means for instructing the control circuit, and turning off the LED of the LED lighting device corresponding to the black portion.
A lighting device characterized by: 4. An LCD display device comprising an LCD, an LCD control circuit for controlling the LCD display device, an LED for individually irradiating light to a light transmitting portion of each pixel of the LCD for each pixel, and An LED lighting device comprising wiring for LED driving, an LED control circuit for driving the LED lighting device, and position information of a window screen accessed by an input device among window windows provided to the LCD display device by the LCD control circuit. The LE corresponding to the window portion
A lighting device characterized by increasing the brightness of the LED of the D lighting device. 5. An LCD display device comprising an LCD, an LCD control circuit for controlling the LCD display device, an LED for individually irradiating a light transmitting portion of each pixel of the LCD with light for each pixel, and An LED lighting device comprising wiring for LED driving, an LED control circuit for driving the LED lighting device, and position information of a window screen which is not accessed from the input device for a certain period of time in a window screen provided to the LCD display device by the LCD control circuit. A means for grasping, said win not being accessed
A lighting device characterized in that the brightness of the LED of the LED lighting device corresponding to a dow portion is reduced stepwise. 6. An illuminance detection circuit for detecting the illuminance of the surrounding environment, and when the surroundings are bright based on information of the illuminance detection circuit, the illuminance emitted from the LED lighting device and passed through the LCD display device is used as the surroundings. 6. An instruction input / output control unit which emits light from the LED lighting device when the surroundings are darker than the illuminance and issues a command to make the illuminance passing through the LCD display device darker than the surrounding illuminance. Lighting equipment. 7. A personal computer using the lighting device according to claim 1. 8. A digital still camera using the lighting device according to claim 1. 9. A camera movie using the lighting device according to claim 1. 10. A mobile phone using the lighting device according to claim 1. 11. An information portable terminal using the lighting device according to claim 1.