CN100435006C - Backlight, display apparatus and light source controlling method - Google Patents

Abstract

A backlight for illuminating the back of a display section includes a plurality of light sources disposed in positions corresponding to a display area of the display section; a diffusion member configured to transmit light from the light sources to the display section; a photo-sensor; a light guiding member configured to introduce the light from the light sources to the photo-sensor for detection; and an arithmetic operation processing section configured to calculate the luminance or chromaticity of each of the light sources from the luminance or chromaticity detected by the photo-sensor.

Description

Backlight, display device and light source control method

The mutual reference of related application

The present invention comprises with the Japanese patent application JP 2005-303405 that submitted to Jap.P. office on October 18th, 2005 and submitted to the relevant theme of Japanese patent application JP 2006-223378 of Jap.P. office on August 18th, 2006, and the whole contents of these patented claims is being hereby incorporated by reference.

Technical field

The present invention relates to typically to be applicable to liquid crystal display backlight, comprise display device backlight and be used to control the light source control method of back lighting.

Background technology

In liquid crystal display, the pixel itself that is disposed on the display board is not luminous.So, be the back side that is arranged in display board backlight, thus make the back side of display board by backlight illumination display image and so on.Along with the screen size increase of liquid crystal display, the display area of display board is tending towards increasing, and own size backlight also significantly increases.

Fig. 8 A and 8B show the example backlight at the back side of the display board that is disposed in liquid crystal display in the past.More specifically, Fig. 8 A shows backlight from what see previously, and Fig. 8 B shows see from the side backlight.With reference to Fig. 8 A and 8B, shown backlight in, cold-cathode fluorescence lamp (CCFL) is used as light-emitting component.Lamp box 1 and a plurality of cold-cathode fluorescence lamps 2 that are disposed in the lamp box 1 and flatly extend with vertical row of comprising backlight.Reflector plate 6 is disposed in the back side of cold-cathode fluorescence lamp 2.Diffusing panel 4 is disposed in the front of lamp box 1, is then arranging cold-cathode fluorescence lamp 2 in the lamp box.Should be pointed out that with respect to backlight and arranging that the face of display board is called as the front, and another face is called as the back side or back.This is equally applicable to the following description here.Particularly, on Fig. 8 B, the left side is the front.Diffusing panel 4 is for example formed by the acrylic sheet or the plate of size with the display area that is substantially equal to display board and predetermined thickness, and like this, it can diffused light.In addition, a plurality of diffusion disks are disposed in the front of diffusing panel 4.Diffusion disk 3 can be formed by the film of the resin material with such characteristic so that for example it provides and has certain directivity characteristics.

Another example of the structure of Fig. 9 A and 9B display backlight wherein provides dividing plate between some adjacent light sources.Especially, Fig. 9 A shows backlight from what watch previously, and Fig. 9 B shows watch from the side backlight.With reference to Fig. 9 A and 9B, except above-mentioned dividing plate, the shown structure identical that have backlight with the structure backlight of Fig. 8 A and 8B.Especially, dividing plate 7 is disposed between some adjacent cold-cathode fluorescence lamps in a plurality of cold-cathode fluorescence lamps 2, these cold-cathode fluorescence lamps are arranged in the lamp box 1, so that can be introduced in diffusing panel 4 from the luminous flux of cold-cathode fluorescence lamp 2, and do not mix mutually.

Under the occasion of utilizing the structure shown in Fig. 9 A and the 9B, can synchronously realize the flicker of some light source with display image, promptly turn-off.Particularly, be displayed under the occasion of having used liquid crystal display backlight at image, the light emitting control backlight that is called as flicker is used to guarantee live image such as high responsiveness sometimes.More specifically, LCD panel enters a kind of state temporarily, and wherein its show state is unfixed in shows signal is written into time period of layout pixel onboard.This state is possibly by user's perception and worsen the response of the picture quality, particularly live image of display image.So in shows signal was written to time period in the plate, light source backlight was turned off on the back side of relevant horizon light,, thereby strengthen the response of live image so that can be from source reflection light.Being configured to as under the occasion of seeing on Fig. 9 A and the 9B, from adjacent light source at dividing plate 7--the luminous flux that is cold-cathode fluorescence lamp 2--sits on the top of the other.So, can realize scitillation process suitably.After this, the concrete example of the light emitting control that wherein involves scitillation process is described in conjunction with the preferred embodiments of the present invention.

Japanese patent publication No.2003-50569 discloses a kind of liquid crystal display device, and luminous (connection/shutoff) control wherein backlight is synchronously carried out with the rewriting of image, so that guarantee the visuality of high live image.

Brief summary of the invention

Mention in passing, when from the luminous flux of light source by as dividing plate in Fig. 9 A and 9B backlight when separating, if the illumination unevenness of light source, then display image is subjected to heteropical infringement of brightness, causes deterioration of image.Especially, if having some heterogeneity in the brightness or on colourity from the luminous flux of cold-cathode fluorescence lamp 2, then this can cause the heterogeneity and heterogeneity that the brightness of display image is provided of the brightness of seeing as one side from the front.This causes the deterioration of image of display image.Emission light is to be caused by the dispersiveness in the brightness of light source-(in described example, cold-cathode fluorescence lamp)-originally had in this heterogeneity on brightness or the colourity.The deterioration development degree that heterogeneity on brightness or the colourity also causes owing to secular variation sometimes causes

A possible solution of above-mentioned problem is that optical sensor is fixed near each light source that is disposed in backlight so that from the brightness of the light of light source according to being proofreaied and correct individually respectively by the brightness or the colourity of light sensors.Yet, if the many like that optical sensors that equal number of light sources are provided, for an optical sensor that needs backlight are very a large amount of.This causes structurally complicated widely problem backlight.

Though should be pointed out that the above description problem that mainly is arranged to flicker wherein backlight, in this structure that dividing plate is not provided shown in Fig. 8 A and 8B, also involve from the heterogeneity problem of the luminance brightness of light emitted.

Summary of the invention

So requiring provides a kind of display device backlight, a kind of and a kind of light source control method, can carry out simply by them and do not show heteropical smooth emission control.

According to embodiments of the invention, provide a kind of being used to shine the backlight of display part, comprise that a plurality of light sources, diffusing member, single optical sensor, photoconduction draw parts and arithmetic operation processing section.A plurality of light sources are corresponding to the viewing area of display part and be arranged.Diffusing panel is configured to the light from light source is sent to the display part.Photoconduction draws parts and is configured to the light from light source is directed to optical sensor.Arithmetic operation processing section is configured to calculate according to optical sensor detected brightness or colourity from the light that is drawn parts by photoconduction and guide the brightness or the colourity of each light source.

For backlight, can be by the brightness or the colourity of the light of a plurality of light emitted by using a limited number of optical sensor detected.Therefore, the brightness of each light source of preparing or colourity can be detected by simple structure.And, make and can implement by simple structure the control of the light emission state homogenising of light source.

Description of drawings

Fig. 1 is the block diagram of the configuration of display application liquid crystal display of the present invention;

Fig. 2 A is the synoptic diagram that shows the scanning flicker backlight of liquid crystal display to 2F;

Fig. 3 A is the synoptic diagram of example of the light emission state of display backlight to 3F;

Fig. 4 A is the oscillogram that shows the optical sensor output of liquid crystal display to 4D;

Fig. 5 to 7 is block diagrams of the configuration of display application different liquid crystal display of the present invention;

Fig. 8 A and 8B are the synoptic diagram that shows the configuration of example backlight in the past;

Fig. 9 A and 9B are the synoptic diagram that shows the configuration of another example backlight in the past; And

Figure 10 is the heteropical synoptic diagram of demonstration that shows for the appearance backlight of Fig. 9 A and 9B.

Embodiment

At first the first embodiment of the present invention is described referring to figs. 1 through 4D.

In the present embodiment, the present invention is applied to liquid crystal display.The example of total configuration of liquid crystal display at first, is described with reference to Fig. 1.Should be pointed out that on Fig. 1,, show the planimetric map and the vertical cross-section diagram of liquid crystal display with the relation that crosses one another overlapping for the ease of understanding.The vision signal or the picture signal that are input to liquid crystal display are provided to LCD image display control circuit 11, and it produces and is used to drive the signal of LCD panel 12 so that carry out display action according to vision signal.The display drive signals of Chan Shenging is provided to LCD panel 12 like this, and a shows signal is written to each pixel that is disposed on the LCD panel 12 thereon.Writing of shows signal for example is synchronously to carry out with the frame period that offers its vision signal in the time period of a frame.

Backlight 20 are disposed in the back side of LCD panel 12.In the present embodiment, backlight 20 comprise cold- cathode fluorescence lamp 21,22, and 23,24,25 and 26 with as light source, these light sources and put in vertical row with and each extend in the horizontal direction.

Backlightly be configured to make that its cold-cathode fluorescence lamp 21 to 26 forms with vertical row are disposed in the lamp box 29, this forms backlight 20.Reflector plate 28 is disposed in the back side of cold-cathode fluorescence lamp 21 to 26.Diffusing panel 14 is disposed in the front of the lamp box 29 that cold-cathode fluorescence lamp 21 to 26 wherein is installed.Diffusing panel 14 has the size of the display area of LCD panel of being substantially equal to 12, and is for example formed by acrylic sheet or plate, so that its diffused light.And, dividing plate 31 to 35 is disposed between some adjacent fluorescent lights in the cold-cathode fluorescence lamp 21 to 26 in the lamp box 29, so that can be introduced in diffusing panel 14 from the luminous flux of cold-cathode fluorescence lamp 21 to 26 and do not mix with the luminous flux of adjacent lamp from other.

The lighting or connecting of cold-cathode fluorescence lamp 21 to 26/turn-off by the light emissioning controling signal control that is added to cold-cathode fluorescence lamp 21 to 26 from light countdown circuit 15 respectively individually.The vertical synchronizing signal VS of vision signal and horizontal-drive signal HS are provided for light countdown circuit 15 from LCD image display control circuit 15, like this, 15 pairs of cold-cathode fluorescence lamps of light countdown circuit, 21 to 26 adjoining lands are carried out interim turn off process.One of cold-cathode fluorescence lamp 21 to 26 is turned off and a no longer radiative position is consistent mutually with one the horizontal position that writes of carrying out thereon the pixel of the LCD panel 12 of the front that is disposed in one of cold-cathode fluorescence lamp 21 to 26 of being turned off.Therefore, the scitillation process of describing in background note of the present invention more than is achieved.

In addition, in the present embodiment, two photoconductions draw the right-hand member that parts 41 and 42 are disposed in lamp box 29, are introduced in respectively and are fixed on photoconduction and draw optical sensor 43 and 46 on parts 41 and 42 so that enter luminous flux that photoconduction draws parts 41 and 42 from the position of cold-cathode fluorescence lamp 21 to 26.Photoconduction draw parts 41 and 42 by such as, for example, the such transparent material of acrylic materials is made.

More specifically describe photoconduction below and draw parts 41 and 42.From the top fluorescent light of arranging in order 21 that is in first row, the position that is in the fluorescent light 22 of second row and is in the fluorescent light 23 of the third line is to select like this, make from fluorescent light 21, first photoconduction that 22 and 23 luminous flux is introduced at the right-hand member of lamp box 29 draws parts 41, is introduced in the optical sensor 43 on the plate 44 that is set at backlight 20 upper end then.First photoconduction draws parts 41 and has such shape, makes it with the luminous flux of different mutually angle reflections from fluorescent light 21,22 and 23, so that luminous flux is incorporated into single optical sensor 43.Light path is independently represented by each arrow mark of Fig. 1 in this example.

On the other hand, be in the fluorescent light 24 of fourth line, the fluorescent light 26 that is in the fluorescent light 25 of fifth line and is in the 6th row is to select like this, make from fluorescent light 24, second photoconduction that 25 and 26 luminous flux is introduced at the right-hand member of lamp box 29 draws parts 42, is introduced in the optical sensor 46 on the plate 47 that is set at backlight 20 lower end then.Second photoconduction draws parts 42 such shape, makes it with the luminous flux of different mutually angle reflections from fluorescent light 24,25 and 26, so that luminous flux is incorporated into single optical sensor 46.Light path is independently represented by each arrow mark of Fig. 1 in this example.

Optical sensor 43 and 46 so be configured to export corresponding to the voltage signal of the level of incident light thereon with and the voltage signal of each output and the corresponding level of total brightness of the light that arrives from corresponding three fluorescent lights.The voltage signal of being exported converts numerical data to by the analog/ digital converter 45 and 48 that is installed in plate 44 and 47 respectively, is sent to light countdown circuit 15 then.Light countdown circuit 15 sends the digital conversion trigger pulse to analog/ digital converter 45 and 48, and the data of sampling by the sequential of being represented by trigger pulse are sent to light countdown circuit 15.The example of the sequential that is used to sample is described in the back.

Arithmetic circuity 16 is connected to light countdown circuit 15, like this, is added to the optical sensor 43 of light countdown circuit 15 and 46 detection level data and is provided for arithmetic circuity 16.Therefore, the arithmetical operation operation of calculating from the brightness of the light of six cold-cathode fluorescence lamps, 21 to 26 emissions carried out in the arithmetical operation of the operational formula of arithmetic circuity 16 by using prior setting.These operational formulas are described in the back.

Now, be described in the state of writing of the pixel on the LCD panel that image is written to the display device that is disposed in present embodiment and the example of the corresponding relation between the luminance backlight with reference to Fig. 2 A to 2F.As Fig. 2 A in the example shown in the 2F, image writes LCD panel and carries out on a horizontal unit, Fig. 2 A is to the different writing position of 2F display image, they change order in succession.To each figure of 2F, the right half part display image writes the state of writing of LCD panel at Fig. 2 A, and luminous and non-luminous position of left-half display backlight.At the image of Fig. 2 A old graphical representation previous frame to the 2F, and new images is represented the image of present frame.As to 2F, seeing at Fig. 2 A, near near two fluorescent lights that are written in picture signal the locations of pixels of present frame (just at the boundary position between old image and the new image) are to be turned off and non-luminous, and all the other four fluorescent lights then are switched on and are luminous.

Fig. 2 A is more specifically studied to 2F.On Fig. 2 A, the position that image is written into is positioned at the bottom of screen, and two nethermost fluorescent lights 25 and 26 in the middle of six fluorescent lights are turned off and not luminous, and all the other four fluorescent lights are then connected and luminous.If writing position further moves down from this position, then nethermost fluorescent light 26 and uppermost fluorescent light 21 are turned off and are not luminous, shown in Fig. 2 B.Then, if writing position is come the top of screen, then topmost two fluorescent lights 21 and 22 are turned off and not luminous, shown in Fig. 2 C.If after this writing position is moving down from this position adjoining land, then the scram position adjoining land of two fluorescent lights moves down, as Fig. 2 D, shown in 2E and the 2F.Fig. 2 A repeats each frame to the transformation shown in the 2F.

Now, with reference to Fig. 3 A be described in to 3F and 4A to 4D one in the frame luminance (not luminance) and the relation between the detection sequential of two optical sensors 43 and 46.As Fig. 3 A, 3B, 3C, 3D, shown in 3E and the 3F when separate provision under the occasion of first to the 6th luminance that is turned off of the combination of two fluorescent lights in six fluorescent lights, under each luminance, carry out one-time detection by each optical sensor 43 and optical sensor 46.Especially, be to shown in the 3F and under the occasion of regulation,, then obtain the such state shown in Fig. 4 A in first to the 6th luminance as Fig. 3 A in luminance if the output of two optical sensors is detected by adjoining land.At Fig. 4 A, the top optical sensor is represented the output of optical sensor 43, and the bottom optical sensor is represented the output of optical sensor 46.Fig. 4 B shows the vertical sync pulse of display image.Shown in Fig. 4 B, pulse occurs before abutting against first luminance.

Shown in Fig. 4 A, two optical sensors 43 and 46 output repeat to change according to the variation of the residing position of fluorescent light that is turned off.Fig. 4 C indicates to be used to trigger pulse that the output of optical sensor 43 is sampled, and Fig. 4 D shows and will be used for trigger pulse that the output of optical sensor 46 is sampled.To shown in the 4D, the output of optical sensor 43 is acquired under the third state first as Fig. 4 A, and the output of optical sensor 46 is acquired under the 4th to the 6th state.On Fig. 4 A, the sensor output of obtaining under first to the 6th luminance is represented as signal S1 respectively to S6.

The detection data S1 of the top optical sensor 43 under first luminance therein, the detection data S2 of the top optical sensor 43 under second luminance, the detection data S3 of the top optical sensor 43 under the 3rd luminance, the detection data S4 of the bottom optical sensor 46 under the 4th luminance, the detection data S5 of the bottom optical sensor 46 under the 5th luminance, and under the occasion that the detection data S6 of the bottom optical sensor 46 under the 6th luminance is prescribed by this way, if 21,22,23,24,25 and 26 luminous quantity is defined as L1 in order respectively, L2, L3, L4, L5 and L6, then the relational expression between the luminous quantity of optical sensor output and fluorescent light is given as follows:

[formula 1]

S1＝L1+L2+L3

S2＝L2+L3

S3＝L3

$\left[\begin{array}{c}S1\\ S2\\ \mathrm{<figure-callout\; id="3"\; label="S"\; filenames="C20061013562200242.png,C20061013562200244.png"\; state="\{\{state\}\}">S</figure-callout>}3\end{array}\right]=\left[\begin{array}{ccc}1& 1& 1\\ 0& 1& 1\\ 0& 0& 1\end{array}\right]\left[\begin{array}{c}L1\\ L2\\ \mathrm{<figure-callout\; id="3"\; label="L"\; filenames="C20061013562200242.png,C20061013562200244.png"\; state="\{\{state\}\}">L</figure-callout>}3\end{array}\right]$

S4＝L4+L5+L6

S5＝L5+L6

S6＝L6

$\left[\begin{array}{c}S4\\ S5\\ \mathrm{<figure-callout\; id="6"\; label="S"\; filenames="C20061013562200231.png,C20061013562200242.png"\; state="\{\{state\}\}">S</figure-callout>}6\end{array}\right]=\left[\begin{array}{ccc}1& 1& 1\\ 0& 1& 1\\ 0& 0& 1\end{array}\right]\left[\begin{array}{c}L4\\ L5\\ \mathrm{<figure-callout\; id="6"\; label="L"\; filenames="C20061013562200231.png,C20061013562200242.png"\; state="\{\{state\}\}">L</figure-callout>}6\end{array}\right]$

By using this relational expression to find the solution following matrix, the luminous quantity L1 of six cold- cathode fluorescence lamps 21,22,23,24,25 and 26, L2, L3, L4, L5 and L6 are confirmed as:

[formula 2]

$\left[\begin{array}{c}L1\\ L2\\ \mathrm{<figure-callout\; id="3"\; label="L"\; filenames="C20061013562200242.png,C20061013562200244.png"\; state="\{\{state\}\}">L</figure-callout>}3\end{array}\right]=\left[\begin{array}{ccc}1& -1& 0\\ 0& 1& -1\\ 0& 0& 1\end{array}\right]\left[\begin{array}{c}S1\\ S2\\ \mathrm{<figure-callout\; id="3"\; label="S"\; filenames="C20061013562200242.png,C20061013562200244.png"\; state="\{\{state\}\}">S</figure-callout>}3\end{array}\right]$

$\left[\begin{array}{c}L4\\ L5\\ \mathrm{<figure-callout\; id="6"\; label="L"\; filenames="C20061013562200231.png,C20061013562200242.png"\; state="\{\{state\}\}">L</figure-callout>}6\end{array}\right]=\left[\begin{array}{ccc}1& -1& 0\\ 0& 1& -1\\ 0& 0& 1\end{array}\right]\left[\begin{array}{c}S4\\ S5\\ \mathrm{<figure-callout\; id="6"\; label="S"\; filenames="C20061013562200231.png,C20061013562200242.png"\; state="\{\{state\}\}">S</figure-callout>}6\end{array}\right]$

This arithmetical operation process is carried out by arithmetic circuity shown in Figure 1 16.Six fluorescent lights 21 to 26 that obtain by arithmetic circuity 16 the data of each luminosity be sent to light countdown circuit 15.The process that light countdown circuit 15 is proofreaied and correct the luminosity of fluorescent light 21 to 26 according to the data of luminosity.For example realize for the correction of each luminosity by the voltage that control is added to corresponding fluorescent light.Proofread and correct the luminosity correction according to being carried out by two optical sensors 43 and 46 data that detect in this way, the luminosity of six fluorescent lights 21 to 26 always can be corrected to uniform level.For example, even some variation or the secular variation of environment for use occur, always still can guarantee uniform luminescent condition, and can prevent that heterogeneity from appearring in the brightness of the image that shows by backlight illumination.

In this case, draw parts 41 and 42 and two optical sensors 43 and 46 because the liquid crystal display of present embodiment includes only two photoconductions, it has more simply structure compared with the replacement situation that an optical sensor will be provided each light source of six light sources.Therefore, can reduce for producing desired cost backlight.

Referring now to the liquid crystal display of Fig. 5 description according to the second embodiment of the present invention.The liquid crystal display of present embodiment is to have total configuration that is similar to first embodiment for the modification of the liquid crystal display of above first embodiment that describes referring to figs. 1 through 4D and it.So, in the following description, the difference of the liquid crystal display and first embodiment of present embodiment is only described.The liquid crystal display of present embodiment is total is configured to make it comprise single optical sensor, and like this, the brightness of all light sources is detected by single optical sensor, and the brightness of light source is determined in the detection output of different sequential according to single optical sensor.

Particularly, with reference to Fig. 5, be used for that the photoconduction of guiding to single optical sensor 53 from the photoconduction of six cold-cathode fluorescence lamps 21 to 26 is drawn parts 51 and be positioned at backlight 20 the right-hand member of arranging cold-cathode fluorescence lamp 21 to 26, like this, optical sensor 53 detects whole outputs of cold-cathode fluorescence lamps 21 to 26.Photoconduction draws parts 51 and is for example made by acrylic materials.Liquid crystal display also comprises catoptron 52, and it is arranged to be used to reflect by photoconduction draw the light that parts 51 are directed to the center, so that be imported into optical sensor 53.Optical sensor 53 is installed on the plate 54, and obtains signal as numerical data from the analog/digital converter 55 that is installed on the plate 54.Numerical data is sent to light countdown circuit 15.

The luminous quantity data that send from optical sensor 53 are sent to arithmetic circuity 16 ', and pass through the luminous quantity of the arithmetical operation of arithmetic circuity 16 ' according to the luminous quantity data computation cold-cathode fluorescence lamp 21 to 26 that receives.Should be pointed out that because liquid crystal display shown in Figure 5 comprises single optical sensor, so change the operational formula of optical transmission mode and lamp in those of the liquid crystal display shown in must be from Fig. 1 to 4D.Under the occasion that adopts configuration shown in Figure 5, the number of optical sensor is reduced to 1, therefore, can reach the structure of more simplifying.

Referring now to the liquid crystal display of Fig. 6 description according to the third embodiment of the present invention.The liquid crystal display of present embodiment is to have total configuration that is similar to second embodiment for the modification of the liquid crystal display of above second embodiment that describes with reference to Fig. 5 and it.So, in the following description, the difference of the liquid crystal display and second embodiment of present embodiment is only described.With reference to Fig. 6, the shown liquid crystal display according to the 3rd embodiment is to be arranged such that photoconduction draws parts and has the structure of more simplifying generally.Particularly, to draw parts be to be arranged such that it is made by acrylic materials etc. and be used for guide lights to the photoconduction among first and second embodiment as shown in figs. 1 and 4.On the contrary, photoconduction in the present embodiment draws parts and is configured to make it to have the form that is disposed in the reflector plate in the lamp box, and it is parts backlight and light is input to one or two optical sensor.

Particularly, photoconduction draws the right-hand member that hollow component 61 is disposed in lamp box 29, and draws hollow component 61 inwalls at photoconduction and arranging reflection part.In addition, catoptron 62 is disposed in the core of reflection part, so that be introduced in optical sensor 63 by the light of catoptron 62 reflections.Optical sensor 63 is fixed on the plate 64, and the output of optical sensor 63 converts numerical data to by analog/digital converter 65 and carries and be given to light countdown circuit 15 sides.

Under the occasion that liquid crystal display is configured in aforesaid mode, the photoconduction of having eliminated for acrylic materials etc. draws the needs of parts, and can reach simpler light guide structure.

Referring now to the liquid crystal display of Fig. 7 description according to the fourth embodiment of the present invention.The liquid crystal display of present embodiment is to have the configuration that is similar to first embodiment generally for the modification of the liquid crystal display of above first embodiment that describes referring to figs. 1 through 4D and it.So, in the following description, the difference of the liquid crystal display and first embodiment of present embodiment is only described.Particularly, the liquid crystal display of present embodiment uses light emitting diode as light source.Particularly, be disposed in LCD panel 12 the back side backlight 70 be included in the red light emitting diodes 71R that arranges in order in each row to 76R, green LED 71G to 76G and blue LED 71B to 76B.Lamp box 79 is configured to make that the inside of reflector plate 78 is divided into it six partitioning portions in vertical direction by dividing plate 31 to 35, is similar to lamp box shown in Figure 1 29.Each partitioning portion (as shown in Figure 7, they are capable), arrange red coloration light emitting diode, green LED and blue LED in order.

In device shown in Figure 7, the red light emitting diodes 71R of desired quantity, green LED 71G and blue LED 71B are arranged to delegation at the top section along continuous straight runs of lamp box 79, i.e. first row.At second row as next partitioning portion, the red light emitting diodes 72R of desired number, green LED 72G and blue LED 72B are arranged to delegation.At the third line, the red light emitting diodes 73R of desired number, green LED 73G and blue LED 73B are arranged to delegation.In fourth line, the red light emitting diodes 74R of desired number, green LED 74G and blue LED 74B are arranged to delegation.At fifth line, the red light emitting diodes 75R of desired number, green LED 75G and blue LED 75B are arranged to delegation.At the 6th row, the red light emitting diodes 76R of desired number, green LED 76G and blue LED 76B are arranged to delegation.

Two photoconductions draw the right-hand member that parts 41 and 42 are disposed in lamp box 79, are introduced in and are separately fixed at the optical sensor 43 and 46 that photoconduction draws parts 41 and 42 so that be introduced in light that photoconduction draws parts 41 and 42 from the position of light emitting diode.Photoconduction draws parts 41 and 42 and is made by the transparent material as acrylic materials for example.

More specifically describe photoconduction below and draw parts 41 and 42.The light emitting diode 71R that is in first row, 71G and 71B, be in second the row light emitting diode 72R, 72G and 72B and be in the light emitting diode 73R of the third line, 73G and 73B place in order from top, so that first photoconduction that is introduced at the right-hand member of lamp box 79 from their light draws parts 41, thereby make light be introduced in to be fixed on optical sensor 43 on the plate 44 of backlight 70 upper end.First photoconduction draws parts 41 such shape: for the luminous flux from the light emitting diode of first, second and the third line is incorporated into single optical sensor 43, it is with different angle reflection flux mutually.

Simultaneously, be in the light emitting diode 74R of fourth line, 74G and 74B, be in the light emitting diode 75R of fifth line, 75G and 75B, with the light emitting diode 76R that is in the 6th row, 76G and 76B place like this, make second photoconduction that is introduced at the right-hand member of lamp box 79 from their light draw parts 42, thereby make light be introduced in to be fixed on optical sensor 46 on the plate 47 of backlight 70 lower end.Second photoconduction draws parts 42 also such shape: for the luminous flux from the 4th, the 5th and the 6th light emitting diode of going is incorporated into single optical sensor 46, it is with mutual different angle reflection flux.

Optical sensor 43 and 46 is configured to export the voltage signal corresponding to the level that incides the light on it.Particularly, the voltage signal of each optical sensor 43 and 46 outputs and the corresponding level of total brightness of the luminous flux that arrives from corresponding triplex row light emitting diode.Convert numerical data from the voltage signal of optical sensor 43 or 46 outputs to by the analog/ digital converter 45 or 48 that is fixed on 44 or 47, be sent to light countdown circuit 15 ' then.Light countdown circuit 15 ' sends the digital conversion trigger pip to analog/digital converter 45 or 48.Therefore, the sequential of representing with the trigger pulse data of sampling are sent to light countdown circuit 15 '.

Arithmetic circuity 16 " be connected to light countdown circuit 15 ', like this, be provided to the optical sensor 43 of light countdown circuit 15 ' and 46 detection level data and just be provided to arithmetic circuity 16 ".Arithmetic circuity 16 " therefore carry out the arithmetical operation process that is used for calculating in the emission luminance brightness of six light emitting diodes of going by the arithmetical operation of wherein having used the operation expression group in advance.For operation expression, can use above those formula that in the explanation of first embodiment, provide.

Because the liquid crystal display of present embodiment is disposed in aforesaid mode, using under the occasion of light emitting diode as light source, also can apply similar radiative brilliance control, and can expect that similarly good image shows light source.Should be understood that, though the number of red light emitting diodes, green LED and blue LED is to equate mutually in the device of Fig. 7, but the light emission light characteristic according to light emitting diode can be arranged redness, green and the blue LED of different numbers, so that can obtain white backlight.

Should be pointed out that the liquid crystal display at Fig. 7, each optical sensor 43 and 46 is that conduct forms for the sensor that is used for sensed luminance, and carries out the processing of the emission luminance brightness of calibration light source according to the output of sensor.Yet each optical sensor 43 and 46 can detect colourity in addition.Detected in this manner by optical sensor 43 and 46 under the occasion of colourity, the light emission measure of colored light emitting diode is controlled according to the detected value of colourity, to carry out the correction of colourity, just, proofreaies and correct the deviation to white.Under the occasion of carrying out colour correction in this manner, can obtain better light backlight.The control example of light emission measure that should be pointed out that light emitting diode or is controlled the time period that this electric current offers light emitting diode as being that control offers the magnitude of current of light emitting diode.

Use in first to the 3rd embodiment described above in addition under the occasion of cathode-ray fluorescent lamp, the colourity of fluorescent light can decide like this so that the glow color of light source can independently be proofreaied and correct according to judgement.

In addition, though, among the embodiment described above, used cathode-ray fluorescent lamp or light emitting diode as light source, some other light source also can use as hot-cathode fluorescent lamp, so that the brightness of light source and colourity are corrected.Simultaneously, when using light emitting diode, for example, also can use the light emitting diode that emits white light.In addition, the present invention also can be used for the light source of number of different types, for example uses the combination of cold-cathode fluorescence lamp and light emitting diode.

In addition, in the above-described embodiment, light source is divided into six light sources in vertical direction.Yet light source also can be divided into a plurality of light sources in the horizontal direction, therefore becomes matrix.In this case, the brightness of light source is detected and be corrected by using a limited number of optical sensor.

In addition, in the above-described embodiment, the present invention is applied to the backlight of configuration like this, and making has a partition member or dividing plate to be disposed between the adjacent light source.Yet the present invention also can be applied to other back light apparatus, and it does not comprise partition member and allow and mixes mutually from the luminous flux of adjacent light source.Yet, in this case, must determine brightness of each light source or the like, also to consider influence from the light of adjacent light source.

Those skilled in the art should see, under the situation in the scope that belongs to claims or their equivalent, can make various modifications, combination, sub-portfolio and change according to design needs and other factors.

Claims (13)

1. One kind be used for to the back side of display part throw light on backlight, comprising:

   A plurality of light sources are arranged to corresponding with the viewing area of described display part;

   Diffusing panel is configured to the light from described light source is sent to described display part;

   Single optical sensor;

   Photoconduction draws parts, is configured to being directed to described optical sensor from the light of each in the described light source, makes the brightness or the colourity of described all described light sources of light sensors; And

   Arithmetic operation processing section is configured to calculate according to described optical sensor detected brightness or colourity from the light that is drawn component lead by described photoconduction the brightness or the colourity of each described light source.
2. 2. backlight according to claim 1, wherein said light source is grouped into first and second groups, and drawing parts, described photoconduction comprises that a pair of photoconduction draws component unit and described optical sensor comprises a pair of optical sensor unit, each draws component unit by described photoconduction independently and is introduced in described optical sensor unit from the light of the described light source in first and second groups, and described arithmetic operation processing section is calculated the brightness or the colourity of each described light source according to described optical sensor detected brightness or colourity from the light that is drawn component lead by described photoconduction.
3. 3. backlight according to claim 1, wherein the brightness or the colourity of each independent light source is corrected in the result that handles according to the arithmetical operation of being undertaken by described arithmetic operation processing section of the brightness of each described light source or the colourity described light source of calculating.
4. 4. backlight according to claim 1, wherein said arithmetic operation processing section carry out control so that described light source each synchronously glimmer with the frame period that will be displayed on the picture signal on the described display part individually, and the light that decision is controlled by this flicker in which light source of described light source is imported into described optical sensor so that calculate the brightness or the colourity of each described light source.
5. 5. backlight according to claim 1, wherein each described light source is a fluorescent light.
6. 6. backlight according to claim 1, wherein each described light source is a light emitting diode.
7. 7. display device comprises:

   The display part is configured to show the image corresponding to received image signal; And

   Backlight, be used for being thrown light in the back side of described display part;

   Described backlight comprising:

   A plurality of light sources are arranged to corresponding with the viewing area of described display part;

   Diffusing panel is configured to the light from described light source is sent to described display part;

   Single optical sensor;

   Photoconduction draws parts, is configured to being directed to described optical sensor from the light of each in the described light source, makes the brightness or the colourity of described all described light sources of light sensors; And

   Arithmetic operation processing section is configured to according to brightness or the colourity of being calculated each described light source by described optical sensor detected brightness or colourity from the light that is drawn component lead by described photoconduction.
8. 8. according to the display device of claim 7, wherein said light source is grouped into first and second groups, described photoconduction draws parts and comprises that a pair of photoconduction draws component unit and described optical sensor comprises a pair of optical sensor unit, each draws component unit by described photoconduction individually and is introduced in described optical sensor unit from the light of the described light source in first and second groups, and described arithmetic operation processing section is according to brightness or the colourity of being calculated each described light source by described optical sensor detected brightness or colourity from the light that is drawn component lead by described photoconduction.
9. 9. according to the display device of claim 7, wherein said arithmetic operation processing section is carried out and is made each control of synchronously glimmering with the frame period of described received image signal individually of described light source, and the light that decision is controlled which light source in the described light source by this flicker is imported into described optical sensor so that calculate the brightness or the colourity of each described light source.
10. 10. according to the display device of claim 7, wherein the brightness or the colourity of each the independent light source in the described light source that calculates of the result that handles according to the arithmetical operation of being undertaken by described arithmetic operation processing section of the brightness of each described light source or colourity are corrected.
11. 11. according to the display device of claim 7, wherein each described light source is a fluorescent light.
12. 12. according to the display device of claim 7, wherein each described light source is a light emitting diode.
13. 13. one kind is used to contrast the brightness of the light source that obviously shows the back side partly and the light source control method that colourity is controlled, may further comprise the steps:

    By use light sensors that its quantity is less than quantity of light source from the brightness or the colourity of the light of the corresponding a plurality of light sources arranged of the surf zone of described display part;

    According to by described light sensors to brightness or colourity brightness or the colourity of calculating each described light source; And

    Brightness or colourity according to each the described light source that calculates are controlled described light source respectively individually.

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