CN1327149A

CN1327149A - Detector for light ray emitted from plane light source

Info

Publication number: CN1327149A
Application number: CN00118072A
Authority: CN
Inventors: 卢志勇
Original assignee: Acer Computer Co Ltd
Current assignee: BenQ Corp
Priority date: 2000-06-07
Filing date: 2000-06-07
Publication date: 2001-12-19
Anticipated expiration: 2020-06-07
Also published as: CN1115552C

Abstract

he detector for light raw emitted from planar light source with light emitting plane in lower position includes a light sensor below the planar light source, with sensing plane in the upper part and parallel with the said light emitting plane; a light blocking board of opaque material, in the sensing plane and with several holes; and a controller connected electrically to the light sensor to read out the sensed signal of the light sensor and to detect the light rays from the planar light source.

Description

Be used for the pick-up unit of the light that the detection plane light source sent

The present invention relates to a kind of pick-up unit, particularly a kind of pick-up unit that is used for the light that the detection plane light source sent.

General planar light source, LCD (liquid crystal display for example, LCD) panel or be arranged in scanner (scanner) or the LCD in backlight (back light), all need to carry out the detection of brightness, uniformity coefficient or even the colour temperature (color temperature) of light, guaranteeing the luminescent quality of light source, and can be used as the foundation of adjusting the equal light pattern on the backlight.Traditional a kind of detection mode is to utilize a brightness photometer to come each test point on the light-emitting area of measurement plane light source, obtaining the brightness value of each test point, and further calculates its uniformity coefficient.But, test point of every measurement, just necessary mobile brightness photometer when test point is too much, not only can increase operational inconvenience to the precalculated position, also can expend many Measuring Time.Traditional another kind of detection mode is to utilize a digital still camera (digital camera) to read brightness value or GTG value on the light-emitting area of whole planar light source, further calculates its uniformity coefficient again.Though this detection mode is rapider, for the emergent ray of the marginal portion of light-emitting area, not only brightness is less, and digital still camera can't read the light of vertical ejaculation, can make the data that reads produce slightly error.

Therefore, fundamental purpose of the present invention is to provide a kind of pick-up unit that is used for the light that the detection plane light source sent, can be accurately and the light that promptly detects planar light source and sent.

Please refer to Fig. 1 and Fig. 2, Fig. 1 and Fig. 2 are the synoptic diagram of the pick-up unit 10 of first embodiment of the invention.The pick-up unit 10 of first embodiment of the invention is to be used for detecting the light that the light-emitting area 14 of the downside of a planar light source 12 is sent.Pick-up unit 10 includes a housing 16, its upper end is provided with an opening 18, one OPTICAL SENSORS 20 is being installed in the opening 18 of housing 16 along the mode that level or vertical direction move, it includes the upside that a sensing face is positioned at OPTICAL SENSORS 20, one photoresistance dividing plate 22 is located on the light sensing face of OPTICAL SENSORS 20, one control device 23 is electrically connected on OPTICAL SENSORS 20, be used for reading the sensing signal that OPTICAL SENSORS 20 is produced, and one drive unit 25 be electrically connected on control device 23, be used for horizontal drive OPTICAL SENSORS 20 and photoresistance dividing plate 22.

When detection plane light source 12, be that planar light source 12 flatly is positioned on the opening 18, so that the light-emitting area 14 of planar light source 12 down, then the light sensing face of OPTICAL SENSORS 20 can be parallel to each other with the light-emitting area 14 of planar light source 12, and the vertical interval between light sensing face and the light-emitting area 14 can be less than a specific distance, and the size of this specific distance is to be decided by the hole depth of a plurality of holes 24 and aperture.When the light-emitting area 14 of planar light source 12 emitted beam, light can be projected on the light sensing face of OPTICAL SENSORS 20 via a plurality of holes 24 of photoresistance dividing plate 22, and then forms a plurality of optical sensing areas that do not overlap each other 26.Each optical sensing area 26 be via the position thereon hole 24 and sense the light that the corresponding test zone 28 on the light-emitting area 14 of planar light source 12 is sent, and the vertical interval between light sensing face and the light-emitting area 14 is less than a specific distance, so each test zone 28 on the light-emitting area 14 of planar light source 12 all can not overlap each other.

See also Fig. 6 and Fig. 7, Fig. 6 is the top view of photoresistance dividing plate 22, and Fig. 7 is the cut-open view of photoresistance dividing plate 22 along Fig. 6 tangent line 7-7.In the present embodiment, OPTICAL SENSORS 20 is that (charge coupled device, CCD), its sensing face is line style, and photoresistance dividing plate 22 is to make with opaque material, which is provided with the hole 24 that a plurality of line styles are arranged for a charge-coupled image sensor.The thickness of photoresistance dividing plate 22 is that the diameter of 10mm, each hole 24 is that spacing between 2mm, the hole 24 is that the upper limb of 15mm and photoresistance dividing plate 22 and the distance of light-emitting area 14 are 20mm, and each test zone 28 on the light-emitting area 14 of planar light source 12 all can not overlap each other as shown in Figure 7.

In addition, control device 23 meeting driver 25 with horizontal drive OPTICAL SENSORS 20 and photoresistance dividing plate 22, make OPTICAL SENSORS 20 be scanned the light-emitting area 14 of whole planar light source 12.In the light-emitting area 14 of OPTICAL SENSORS 20 at plane of scanning motion light source 12,23 of control device can read the sensing signal that each optical sensing area 26 on the light sensing face is produced, the light that is sent with each corresponding test zone 28 on the light-emitting area 14 of detection plane light source 12.And control device 23 can convert the sensing signal that is read to brightness value or colour temperature, and further calculates the uniformity coefficient of whole light-emitting area emitted light.

Owing to light can be projected to via a plurality of holes 24 of photoresistance dividing plate 22 on the light sensing face, and then form corresponding a plurality of light sensings zone 26, therefore pick-up unit 10 can detect the light that a plurality of test zones 28 are sent simultaneously, makes whole testing process become rapider.And according to the hole depth of hole 24 and the design in aperture, vertical interval between light sensing face and the light-emitting area 14 is less than specific distance, can make the area of each 26 corresponding test zone 28 in light sensing zone become less, so the sensing signal that senses can be more near actual state.

With reference to figure 3 and Fig. 4, Fig. 3 and Fig. 4 are the diagrammatic cross-section of the pick-up unit 30 of second embodiment of the invention.In the pick-up unit 30 of second embodiment of the invention, include an attenuator (neutraldensity filter) 32 in addition, flatly be arranged at the upside (as shown in Figure 3) of photoresistance dividing plate 22, or flatly be arranged between the OPTICAL SENSORS 20 of photoresistance dividing plate 22 (as shown in Figure 4), be used for weakening the light that the light-emitting area 14 of planar light source 12 is sent, with avoid OPTICAL SENSORS 20 can be because light luminance be too high the phenomenon of generation voltage saturation.

With reference to figure 5, Fig. 5 is the diagrammatic cross-section of the pick-up unit 40 of third embodiment of the invention.In order to improve the detection efficiency of pick-up unit 40, in the pick-up unit 40 of third embodiment of the invention, a plurality of OPTICAL SENSORS 20 are set in housing 16, and on the light sensing face of each OPTICAL SENSORS 20, a photoresistance dividing plate 22 are set.When operation detection device 40, can set the type of drive of drive unit 25, mode with level drives each OPTICAL SENSORS 20 simultaneously, and the shiftable haulage line of each OPTICAL SENSORS 20 is not overlapped each other, then all OPTICAL SENSORS 20 can scan the light-emitting area 14 of whole planar light source 12 in the short period of time.For the bigger flat luminous source of area, such design can effectively be shortened the time of detecting light under the considering of accuracy.

In the above-described embodiments, planar light source 12 can not move, and the work of detection is to be carried out by mobile OPTICAL SENSORS 20 and photoresistance dividing plate 22.Yet the work that detects also can be by plane of motion light source 12, and not mobile OPTICAL SENSORS 20 and photoresistance dividing plate 22 are reached same purpose.In addition, if the length of OPTICAL SENSORS 20 and photoresistance dividing plate 22 is greater than the length or the width of planar light source 12, just then

OPTICAL SENSORS

20 and 22 need of photoresistance dividing plate move towards single direction and can obtain required detection data.On the sensing face of OPTICAL SENSORS 20, if photoresistance dividing plate 22 all is provided with a plurality of holes 24 in the mode of matrix on two vertical direction, and the area of the sensing face of OPTICAL SENSORS 20 is the areas greater than planar light source 12, does not then need to relatively move between OPTICAL SENSORS 20 and the planar light source 12 just to reach the purpose of detection plane light source 12.These changes of doing based on the present invention's spirit all should belong within this patent category.

Compare with the traditional detection device, the pick-

up unit

10,30,40 that is used for the light that detection plane light source 12 sent of the present invention, be a plurality of holes 24 that utilize photoresistance dividing plate 22, with ray cast to the light sensing face of OPTICAL SENSORS 20, to form a plurality of light sensings zone 26, the sensing signal that is read by control device 23 converts brightness value or computing outgoing light homogeneity to again.Therefore pick-up unit of the present invention can be accurately and is promptly detected and exceed the light that area source 12 is sent.

The above only is the preferred embodiments of the present invention, and equivalent variations and modification according to claim of the present invention is made all should belong among the scope of patent of the present invention.

Fig. 1 and Fig. 2 are the synoptic diagram of the pick-up unit of first embodiment of the invention.

Fig. 3 and Fig. 4 are the diagrammatic cross-section of the pick-up unit of second embodiment of the invention.

Fig. 5 is the diagrammatic cross-section of the pick-up unit of the present invention the 3rd embodiment.

Fig. 6 is the top view of Fig. 2 photoresistance dividing plate.

Fig. 7 is the cut-open view of Fig. 6 photoresistance dividing plate along tangent line 7-7.Illustrated symbol description

10,30,40 pick-up units

12 planar light sources, 14 light-emitting areas

16 housings, 18 openings

20 OPTICAL SENSORS, 22 photoresistance dividing plates

23 control device, 24 holes

25 drive units, 26 light sensing zones

28 test zones, 32 attenuators

Claims

1. a pick-up unit is used for detecting the light that a planar light source is sent, and the light-emitting area of described planar light source is positioned at the downside of described planar light source, and described pick-up unit comprises:

One OPTICAL SENSORS is located under the described planar light source, and the sensing face of described OPTICAL SENSORS is positioned at the upside of described OPTICAL SENSORS, and the light sensing face of described OPTICAL SENSORS parallels with the light-emitting area of described planar light source;

One photoresistance dividing plate is located on the light sensing face of described OPTICAL SENSORS, and described photoresistance dividing plate is made with opaque material, which is provided with a plurality of holes; And

One control device is electrically connected on described OPTICAL SENSORS, is used for reading sensing signal that described OPTICAL SENSORS produces to detect the light that described planar light source is sent;

Thereby a plurality of holes of the light that the light-emitting area of wherein said planar light source is sent by described photoresistance dividing plate are projected to and form a plurality of optical sensing areas that do not overlap each other on the described light sensing face, each optical sensing area senses the light that the corresponding test zone on the light-emitting area of described planar light source is sent by position hole thereon, described control device then can read the sensing signal that each optical sensing area produced on the described light sensing face with each corresponding test zone was sent on the light-emitting area that detects described planar light source light.

2. pick-up unit as claimed in claim 1, each test zone on the light-emitting area of wherein said planar light source does not all overlap each other.

3. pick-up unit as claimed in claim 2, vertical interval between wherein said light sensing face and the described light-emitting area is less than a specific distance thereby described a plurality of test zone is not overlapped each other, and described specific distance is decided by the hole depth and the aperture of described a plurality of holes.

4. pick-up unit as claimed in claim 1, wherein said OPTICAL SENSORS are a charge-coupled image sensor.

5. pick-up unit as claimed in claim 1, wherein said control device reads color temperature value or the brightness value of the sensing signal that each optical sensing area produced to calculate each corresponding test zone on the described light sensing face, and detects the uniformity coefficient of the light that described planar light source sends according to this.

6. pick-up unit as claimed in claim 1, wherein said planar light source are a backlight liquid crystal display plate or a panel.

7. pick-up unit as claimed in claim 1, also include a housing, its upper end is provided with an opening, described planar light source flatly be positioned on the described opening and its light-emitting area down, and described photoresistance dividing plate and described OPTICAL SENSORS flatly are installed under the described opening.

8. pick-up unit as claimed in claim 7, the sensing face of wherein said OPTICAL SENSORS is line style, and a plurality of holes on the described photoresistance dividing plate also are the line style arrangement.

9. pick-up unit as claimed in claim 8, wherein said OPTICAL SENSORS and described photoresistance dividing plate are installed in the described housing in a movable manner, are used for the described OPTICAL SENSORS of horizontal drive and described photoresistance dividing plate so that described OPTICAL SENSORS is scanned all light-emitting areas of described planar light source and described pick-up unit includes a drive unit in addition.

10. pick-up unit as claimed in claim 1, wherein said pick-up unit includes an attenuator in addition, flatly be arranged between described planar light source and the described OPTICAL SENSORS, be used for weakening light that described planar light source sends with avoid described OPTICAL SENSORS can be because illumination be too high the generation saturated phenomenon.

11. pick-up unit as claimed in claim 10, wherein said attenuator is arranged at the upside of described photoresistance dividing plate.

12. pick-up unit as claimed in claim 10, wherein said attenuator are arranged between described photoresistance dividing plate and the described OPTICAL SENSORS.