JP2009186546A - Projector and projection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector and the like capable of projecting an image with reduced luminance unevenness by suppressing influences of uneven luminous energy even when incident light to a light modulator includes uneven luminous energy. <P>SOLUTION: A projector 100 is configured to include: a plurality of luminous energy measuring sections 190 disposed outside a display region of a light modulator 140 and measuring the luminous energy of incident light to the light modulator 140; a luminous energy distribution determining section 180 determining the distribution of luminous energy of the incident light in the display region based on the luminous energy measured by the plurality of luminous energy measuring sections; and a control value determining section 162 determining a control value for controlling the light modulator 140 in accordance with the distribution. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector and a projection method.

  For example, the arc position of the lamp in the projector may change over time. In such a case, the amount of light incident on the light modulator such as a liquid crystal panel is not uniform in the display area in the light modulator, and the image quality of the projected image is deteriorated. As a technique for dealing with such a change with time, Japanese Patent Application Laid-Open No. 2005-55760 describes a technique for detecting the amount of light adjusted by the light control means and automatically calibrating the light control means according to the detection result. Has been. However, since this method is a method using one optical sensor, the distribution of the light amount in the display area cannot be grasped, and the problem of uneven light amount in the display area cannot be solved.

Japanese Patent Application Laid-Open No. 2004-228948 captures a projected calibration image, divides an image display area in the captured image into a plurality of target areas, and inputs / outputs based on an average brightness index value in each target area. A method for correcting color unevenness by correcting characteristic data is described.
JP-A-2005-55760 JP 2004-228948 A

  However, since the technique disclosed in Japanese Patent Application Laid-Open No. 2004-228948 is a technique for capturing a projected calibration image, it is affected by the screen on which the calibration image is projected, the illumination light applied to the screen, and the like. Therefore, it is necessary to perform correction according to changes with time each time the use environment changes, and inefficiency is lost when correcting unevenness in the amount of light caused by a change in the arc position of the lamp.

  An object of the present invention is to provide a projector capable of projecting an image with reduced luminance unevenness by suppressing the influence of the unevenness in the amount of light even when there is unevenness in the amount of light incident on the optical modulator. It is to provide a projection method.

  In order to solve the above problems, a projector according to the present invention is provided outside a display region of an optical modulator, and includes a plurality of light amount measuring units that measure the amount of light incident on the light modulator, and the plurality of light amounts. Based on the amount of light measured by the measuring unit, a light amount distribution determining unit that determines the distribution of the amount of incident light in the display area, and a control value that determines a control value for controlling the light modulator according to the distribution And a determining unit.

  Further, the projection method according to the present invention is based on a projector having an optical modulator, a plurality of light quantity measuring units provided outside the display area of the optical modulator, a light quantity distribution determining unit, and a control value determining unit. In the image projection method, the plurality of light amount measuring units measure the amount of light incident on the light modulator, and the light amount distribution determining unit is based on the light amounts measured by the plurality of light amount measuring units. Determining a distribution of the amount of incident light in the display area, the control value determining unit determining a control value for controlling the optical modulator according to the distribution, and the optical modulator controlling the control An image is projected toward the projection target region by modulating the incident light based on the value and the input image signal.

  According to the present invention, the projector uses the light amount measured by a plurality of light amount measurement units provided at predetermined positions outside the display region of the light modulator, thereby calculating the distribution of the light amount of incident light in the display region. Since it is possible to determine the control value for controlling the optical modulator according to the distribution, it is possible to suppress the influence of unevenness in the amount of light, and to reduce the brightness unevenness. Can be projected.

  In addition, the light amount distribution determining unit may calculate, as the distribution, a difference value between an average value of light amounts measured by the plurality of light amount measuring units and a measured light amount of each light amount measuring unit or a difference value between an ideal light amount value and a measured light amount. And calculating the output light amount correction value for each adjustment target region in the display region, and the control value determining unit may determine the control value based on the output light amount correction value for each adjustment target region. .

  According to this, the projector calculates the difference in light quantity for each measurement target area of each light quantity measurement unit from the difference value between the average value of the light quantity and the measurement light quantity of each light quantity measurement unit or the difference value between the ideal light quantity value and the measurement light quantity. The correction value and the control value can be determined according to the difference.

  In addition, the control value determination unit is configured for each pixel in the display region based on the output light amount correction value for each adjustment target region and input / output data indicating an output light amount for each input image signal value in the optical modulator. The control value may be determined based on the input image signal value and the signal correction value.

  According to this, since the projector can adjust the output light amount by correcting the input image signal value for each pixel of the display area, the influence of the uneven light amount can be suppressed, and the uneven brightness can be reduced. An image can be projected.

  In addition, the light modulator includes a liquid crystal panel, a driving unit that drives the liquid crystal panel, and a light shielding member provided on an emission side of the incident light with respect to the liquid crystal panel. The incident side of the incident light with respect to the liquid crystal panel is provided at a position facing the light shielding member via the liquid crystal panel, and the control value determining unit is used as the control value for driving the driving unit. The applied voltage to the liquid crystal panel may be determined.

  According to this, the projector can suppress the influence of the light amount unevenness without providing the light amount measurement unit to the observer by providing the light amount measurement unit at the position facing the light shielding member. Also, according to this, since the projector can determine the voltage applied to the liquid crystal panel according to the light quantity measurement result, the influence of the light quantity unevenness in the liquid crystal panel is suppressed, and an image with reduced brightness unevenness is projected. be able to.

  Embodiments in which the present invention is applied to a projector will be described below with reference to the drawings. In addition, the Example shown below does not limit the content of the invention described in the claim at all. In addition, all the configurations shown in the following embodiments are not necessarily essential as means for solving the invention described in the claims.

(First embodiment)
FIG. 1 is a functional block diagram of the projector 100 in the first embodiment. The projector 100 executes a signal input unit 110 for inputting an image signal or the like from a PC (Personal Computer) or the like, and image processing (for example, correction of color, brightness, image shape, etc.) for the input image signal. An image processing unit 120, a lamp 130 that is a kind of light source, a projection lens 150, a light modulator 140 that modulates light from the lamp 130 and outputs the modulated light to the lens 150, a lamp 130, a light modulator 140, and the like The control part 160 which controls is comprised.

  The light modulator 140 includes a liquid crystal panel 144 having an image display area, a light shielding mask 146 which is a kind of light shielding member for preventing light outside the display area from being output, and a drive for driving the liquid crystal panel 144. A portion 142 is included.

  Further, the projector 100 determines the light amount distribution for determining the light amount distribution in the display region of the liquid crystal panel 144 based on the light amount measurement results of the four light amount measuring units 190 provided outside the display region of the liquid crystal panel 144 and the light amount measuring unit 190. The unit 180 is configured to be included. In addition, the control unit 160 includes a control value determining unit 162 that determines a control value for controlling the driving unit 142 according to the distribution determined by the light amount distribution determining unit 180, and the input signal value and the output luminance value are obtained. The associated input / output data 164 and correction data 166 for correcting the input signal value are stored.

  Note that the functions of these units may be implemented in the projector 100 using the following hardware, for example. For example, the signal input unit 110 is an image signal input terminal, the image processing unit 120 is an image processing circuit, the driving unit 142 is a liquid crystal driving circuit, the control unit 160 is a CPU, a RAM, and the light quantity distribution determining unit 180. For example, a CPU or the like, and a luminance sensor or the like may be used as the light amount measurement unit 190.

  Here, the arrangement of the light quantity measurement unit 190 in the optical modulator 140 will be described. FIG. 2 is a front view of the optical modulator 140 in the first embodiment. FIG. 3 is a side view of the optical modulator 140 in the first embodiment.

  For example, the light quantity measuring unit 190-1 is provided at a position opposite to the light shielding mask 146 near the midpoint of the side AB of the display area ABCD of the liquid crystal panel 144, and the light quantity measurement is performed at the position opposed to the light shielding mask 146 near the middle point of the side BC. , A light quantity measuring unit 190-3 is provided at a position facing the light shielding mask 146 near the midpoint of the side CD, and a light quantity measuring unit 190 is located at the position facing the light shielding mask 146 near the midpoint of the side DA. -4 is provided. Thus, since each light quantity measurement part 190 exists in the opposition position of the light shielding mask 146, it cannot be visually recognized from the lens 150 side, ie, a user.

  Further, as shown in FIG. 3, incident light from the lamp 130 enters the light amount measuring unit 190 and the liquid crystal panel 144. The incident light is shielded by the light shielding mask 146, so that only the display area ABCD is transmitted and emitted from the liquid crystal panel 144 as outgoing light. That is, even when the light amount measurement unit 190 is provided, there is no influence on the projected image.

  Next, the input / output data 164 will be described in more detail. FIG. 4 is a diagram showing the input / output data 164 in the first embodiment. FIG. 5 is a graph of the input / output data 164 shown in FIG.

  The input / output data 164 is data indicating, for example, the association between an input signal value output from the image processing unit 120 and a desired output luminance value when the input signal value is input. In FIG. 4, each value is normalized so that the minimum value is 0 and the maximum value is 1023.

  Next, an image projection procedure in the present embodiment will be described. FIG. 6 is a flowchart showing a procedure for projecting an image in the first embodiment. When projector 100 is activated, control unit 160 causes lamp 130 to emit light (step S1).

  When the light amount of the lamp 130 is stabilized after the lamp 130 emits light, the control unit 160 controls the light amount measurement unit 190, and the light amount measurement units 190-1 to 190-4 measure the luminance value of the incident light (step S2). ). The measurement luminance value of the light quantity measurement unit 190-1 is L1, the measurement luminance value of the light quantity measurement unit 190-2 is L2, the measurement luminance value of the light quantity measurement unit 190-3 is L3, and the measurement luminance value of the light quantity measurement unit 190-4 is Let L4.

  The light quantity distribution determining unit 180 calculates an average luminance value LA that is a calculation result of (L1 + L2 + L3 + L4) / 4, and calculates difference values ΔL1 to ΔL4 between LA and each measured luminance value (step S3).

  As shown in FIG. 2, the control value determination unit 162 calculates distances D1 to D4 from the target pixel P to each light quantity measurement unit 190, and calculates a total value DS of D1 to D4 (step S4). For example, when the coordinate of the target pixel P is (x, y), the upper left coordinate of the display area is A (0, 0), and the upper right coordinate of the display area is B (X, 0), the light amount measurement unit 190 The coordinate of −1 is (X / 2, 0). In this case, D1 is, for example, the square root of a value obtained by adding a value obtained by squaring y to a value obtained by squaring (X / 2−x). D2 to D4 are obtained in the same manner.

  The control value determination unit 162 calculates the output luminance correction value ΔL shown in FIG. 5 based on ΔL1 to ΔL4, D1 to D4, and DS (step S5). For example, the control value determination unit 162 calculates the output luminance correction value ΔL in the target pixel based on the influence level of incident light in each light amount measurement unit 190 in the target pixel. More specifically, the influence degree E1 of the incident light in the light amount measurement unit 190-1 in the target pixel P is (DS−D1) / {(DS−D1) + (DS−D2) + (DS−D3) +. (DS-D4)}. The same applies to the influence levels E2 to E4 of the incident light in the light quantity measuring units 190-2 to 190-3 in the target pixel P.

  Therefore, ΔL = ΔL1 × E1 + ΔL2 × E2 + ΔL3 × E3 + ΔL4 × E4. For example, if D1 = 10, D2 = 20, D3 = 50, D4 = 20, DS = 100, ΔL1 = 10, ΔL2 = 20, ΔL3 = 20, ΔL4 = 10, E1 = (100−10) / {( 100−10) + (100−20) + (100−50) + (100−20)} = 0.3. Similarly, E2 = 0.27, E3 = 0.17, and E4 = 0.27. Therefore, in this case, ΔL = 10 × 0.3 + 20 × 0.27 + 20 × 0.17 + 10 × 0.27 = 14.5.

  Note that the control value determination unit 162 may calculate ΔL by appropriately adjusting the total value of E1 to E4 to be 1. In addition, when any of D1 to D4 is 0 or a value close to 0 (for example, 1/10 or less of the maximum distance), the control value determining unit 162 is the light amount measuring unit closest to the target pixel. The difference value of 190 may be used as it is as ΔL.

  The control value determining unit 162 updates the correction data 166 indicating the output luminance correction value ΔL for each target pixel (step S6). The control unit 160 and the light amount distribution determining unit 180 determine whether or not the process for obtaining ΔL is completed for all target pixels (step S7). If not completed, the control unit 160 and the light amount distribution determination unit 180 select the next target pixel and repeat the processes of steps S4 to S7.

  The target pixel may be all the pixels in the display area, or may be a part of the pixels in the display area. When the pixel is a part of the display area, the control unit 160 may perform an interpolation operation using ΔL obtained in the above-described process to obtain ΔL of another pixel.

  As shown in FIG. 5, the control value determining unit 162 determines the adjusted output luminance value L ′ by adding ΔL to the output luminance value L with respect to the input signal value V, and the input signal corresponding to L ′. The values V ′ and the difference value ΔV between V and V ′ can be determined. When the processing for all the target pixels is completed and the correction data 166 is completed, the control value determination unit 162 corrects the input signal value based on the correction data 166 to determine an applied voltage (control value) to the optical modulator 140. (Step S8). For example, when the actual input signal value is V and the output luminance value is L, the control value determining unit 162 determines an applied voltage at which the input signal value is V ′ and the output luminance value is L ′.

  The driving unit 142 drives each pixel of the liquid crystal panel 144 with an applied voltage to each pixel determined by the control value determining unit 162, and the projector 100 displays an image via the liquid crystal panel 144 and the lens 150. Projecting is performed (step S9).

  As described above, according to the present embodiment, the projector 100 uses the light amount measured by the plurality of light amount measurement units 190 provided outside the display region of the light modulator 140, so that the incident light in the display region can be obtained. Therefore, the control value for controlling the light modulator 140 can be appropriately determined according to the distribution, so that the influence of unevenness in the amount of light can be suppressed and the luminance can be reduced. An image with reduced unevenness can be projected.

  Further, according to the present embodiment, the projector 100 can grasp the difference in the light amount for each measurement target region of each light amount measurement unit 190 from the difference value between the average value of the light amount and the measurement light amount of each light amount measurement unit 190. The correction value and the control value can be determined according to the difference.

  In addition, according to the present embodiment, the projector 100 can adjust the output light amount by correcting the input image signal value for each pixel of the display area, and thus can suppress the influence of the uneven light amount. An image with reduced brightness unevenness can be projected.

  In addition, according to the present embodiment, the projector 100 provides the light amount measurement unit 190 at the position opposite to the light shielding mask 146, thereby suppressing the influence of unevenness in light amount without allowing the observer to see the light amount measurement unit 190. Can do. Further, according to the present embodiment, the projector 100 can determine the voltage applied to the liquid crystal panel 144 according to the light quantity measurement result, so that the influence of the light quantity unevenness in the liquid crystal panel 144 is suppressed and the brightness unevenness is reduced. Projected images can be projected.

(Second embodiment)
FIG. 7 is a front view of the optical modulator 140 in the second embodiment. In the second embodiment, the light quantity measuring units 191-1 to 191-4 are provided at the four corners of the display area. Thus, even when the light quantity measuring units 191-1 to 191-4 are provided at the four corners of the display area, the projector 100 obtains the control value for each pixel by the same method as in the first embodiment. Therefore, it is possible to project an image in which the influence of unevenness in the amount of light is suppressed and the unevenness in brightness is reduced.

(Other examples)
In addition, application of this invention is not limited to the Example mentioned above, A various deformation | transformation is possible. For example, the installation positions and the number of the light quantity measuring units 190 and 191 are not limited to the above-described embodiments. For example, the light quantity measuring units 190 and 191 may be provided one at a position outside the display area at the upper left and lower right of the display area (two in total), or the four corners of the display area and the midpoint of each side May be provided one by one at a position outside the display area (8 in total).

  In the above-described embodiment, the difference value between the average luminance value and the measured luminance value is used as ΔL1 to ΔL4. However, the difference value between the ideal light amount value and the measured luminance value may be used. The ideal light quantity value may be a brightness value measured by the light quantity measuring units 190 and 191 in a state where there is no unevenness in the light quantity.

  Further, the projector 100 does not need to execute the above-described uneven light amount correction process every time it is started. For example, the projector 100 performs the above-described uneven light amount correction process when a predetermined period such as every month or every six months elapses. Also good. That is, since the control unit 160 can store the correction data 166, the projector 100 once generates the accurate correction data 166, so that the light amount is measured using the correction data 166 without measuring the light amount. Correction according to unevenness can be performed.

  In addition, the value indicating the light amount is not limited to the luminance value, and various values indicating brightness such as an illuminance value and a Y value (Y value in the XYZ value) can be employed. Further, the light shielding member is not limited to a fixed light shielding member such as the light shielding mask 146, and may be a drivable light shielding member such as a liquid crystal shutter or an iris.

  In the above-described embodiment, the light amount distribution determination unit 180 employs pixels as the adjustment target region and calculates the output light amount correction value for each pixel. However, the adjustment target region is not limited to pixels, It may be a pixel block composed of pixels (for example, 2 × 2 pixels, 3 × 3 pixels, etc.).

  Further, the control value determining unit 162 may simply obtain the distances D1 to D4. For example, when the coordinates of the light quantity measuring units 190 and 191 are (xn, yn) and the coordinates of the target pixel P are (x, y), the control value determining unit 162 determines the absolute value of xn−x and yn−y. The absolute value may be compared and the larger value may be applied as the distance.

  The liquid crystal panel 144 may be three plates (for example, liquid crystal panels corresponding to R, G, and B, respectively). In this case, the light quantity measurement units 190 and 191 may be provided in each liquid crystal panel, may be provided in one liquid crystal panel, or provided immediately before the light separation unit that separates light from the light source. Also good. For example, when the light quantity measurement units 190 and 191 are provided in one liquid crystal panel, the light quantity distribution determination unit 180 estimates the measurement value of the incident light quantity to another liquid crystal panel from the measurement value of the incident light quantity to the liquid crystal panel. May be.

  The projector 100 may be a front projection type or a rear projection type. Further, the function of the projector 100 may be distributed and implemented in a plurality of devices (for example, a PC and a projector).

It is a functional block diagram of the projector in a 1st Example. It is a front view of the optical modulator in a 1st Example. It is a side view of the optical modulator in a 1st Example. It is a figure which shows the input / output data in a 1st Example. It is the figure which graphed the input-output data shown in FIG. It is a flowchart which shows the projection procedure of the image in a 1st Example. It is a front view of the optical modulator in a 2nd Example.

Explanation of symbols

  100 projector, 110 signal input unit, 120 image processing unit, 130 lamp, 140 light modulator, 142 driving unit, 144 liquid crystal panel, 146 shading mask (shading member), 150 lens, 160 control unit, 162 control value determining unit, 164 I / O data, 166 correction data, 180 light quantity distribution determining unit, 190, 191 light quantity measuring unit

Claims (5)

A plurality of light quantity measuring units provided outside the display area of the light modulator, for measuring the quantity of incident light to the light modulator;
A light amount distribution determining unit that determines a distribution of the amount of incident light in the display area based on the light amount measured by the plurality of light amount measuring units;
A control value determining unit that determines a control value for controlling the optical modulator according to the distribution;
Including a projector. The projector according to claim 1, wherein
The light amount distribution determining unit is based on a difference value between an average light amount measured by the plurality of light amount measuring units and a measured light amount of each light amount measuring unit or a difference value between an ideal light amount value and a measured light amount as the distribution. The output light amount correction value for each adjustment target area in the display area is calculated,
The projector, wherein the control value determination unit determines the control value based on the output light amount correction value for each of the adjustment target areas. The projector according to claim 2,
The control value determining unit is configured to input each pixel in the display region based on the output light amount correction value for each adjustment target region and input / output data indicating an output light amount for each input image signal value in the light modulator. A projector that determines a signal correction value, which is a correction value of an image signal, and determines the control value based on the input image signal value and the signal correction value. The projector according to any one of claims 1 to 3,
The light modulator is
LCD panel,
A drive unit for driving the liquid crystal panel;
A light shielding member provided on the exit side of the incident light with respect to the liquid crystal panel;
Including
The light amount measurement unit is provided on the incident side of the incident light with respect to the liquid crystal panel, and is provided at a position facing the light shielding member via the liquid crystal panel,
The projector, wherein the control value determination unit determines an applied voltage to the liquid crystal panel used for driving the driving unit as the control value. A method of projecting an image by a projector having a light modulator, a plurality of light amount measurement units provided outside the display area of the light modulator, a light amount distribution determination unit, and a control value determination unit,
The plurality of light amount measuring units measure the amount of light incident on the light modulator,
The light amount distribution determining unit determines a distribution of the light amount of incident light in the display region based on the light amount measured by the plurality of light amount measuring units,
The control value determining unit determines a control value for controlling the optical modulator according to the distribution,
The light modulator projects an image toward a projection target area by modulating the incident light based on the control value and an input image signal.

Images