JP2014041227A - Projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector capable of changing the ratio between a transmission light transmitting area and a light shielding area and adjusting an improvement level of moving image blur.
SOLUTION: Color separation means for splitting light from a light source into a plurality of color components, light modulation means for performing light modulation for each of the plurality of color components according to a video signal, and light modulated color component lights. A color synthesizing unit; a unit that blocks the color-combined light; and a projection unit that projects the color-combined light. The light-blocking unit includes a plurality of light-blocking units, and the light-blocking ratio of the projection light is changed. The configuration is characterized by being possible.
[Selection] Figure 1

Description

  The present invention relates to a projector device, and more particularly to a projector device having light amount control.

  In recent years, projectors are widely used as video display devices capable of displaying video on a large screen. The projector has a light source such as an ultra-high pressure mercury lamp and a xenon lamp. The projector modulates the illumination light from the light source according to the video signal by the light modulation element, and generates the video light by the projection lens. Images can be displayed by projecting onto the screen.

  In a current projector apparatus, a liquid crystal panel can be given as a typical light modulation element. The driving method of the liquid crystal panel is the hold type driving in which information is always displayed, unlike the impulse type driving used in the CRT or the like. As a problem caused by this driving method, when displaying a moving image, even if the response time of the liquid crystal is shortened, information is always displayed, so the edge portion of the moving image is perceived as blurred due to human visual characteristics. There was a case.

  In view of this, a technique is disclosed in which moving image blur is reduced by rotating a rotating plate provided with a light transmission region and a light non-transmission region and intermittently irradiating light (Patent Document 1).

JP 2005-134463 A

  However, the improvement level of the moving image blur increases as the light shielding area of the projection light increases, but on the other hand, phenomena such as screen flickering and screen darkening also occur. In view of the prior art disclosed in the above-mentioned patent document, since the ratio of the transmission region and the light shielding region is uniquely determined by the rotating plate, there is a problem that it is difficult to adjust the improvement level of moving image blur. Yes.

  Accordingly, an object of the present invention is to provide a projector that can change the ratio of the transmission light transmission area and the light shielding area, and can adjust the improvement level of the motion blur.

  In order to achieve the above object, the present invention provides a color separation unit that splits light from a light source into a plurality of color components, a light modulation unit that modulates light according to a video signal for each of the plurality of color components, and a light modulation. Color synthesizing means for synthesizing each color component light, means for shielding the color synthesized light, and projection means for projecting the color synthesized light, and the light shielding means comprises a plurality of light shielding means. The light blocking ratio of the projection light can be changed.

  According to the present invention, it is possible to provide a projector that can change the ratio of the transmission light transmitting area and the light shielding area and can adjust the improvement level of moving image blur.

Optical system block diagram of the projector of Embodiment 1 Plan view of luminance wheels a and b according to the first embodiment. The figure showing the light-shielding rate when using the brightness wheels a and b of Example 1 Rotation phase control block diagram of Embodiment 1 Rotation phase determination flowchart of embodiment 1 Luminance frame difference histogram detection result example Example of luminance histogram detection result Rotation phase control and light source output control block diagram of embodiment 2

  Hereinafter, a preferred embodiment of a projector apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

  Hereinafter, a first embodiment of the present invention will be described.

  FIG. 1 is an optical system block diagram showing a first embodiment relating to a projector apparatus according to the present invention. The projector device 100 according to the present embodiment includes a light source 101, dichroic mirrors 102 and 103, a mirror 104, polarizing beam splitters 105, 106, and 107, liquid crystal panel elements 108, 109, and 110, an X prism 111, and luminance. A wheel a112, a luminance wheel b113, and a projection lens 114 are included.

  In the projector apparatus shown in FIG. 1, a light source 101 is a light source that outputs white light, such as an ultra-high pressure mercury lamp or a xenon lamp. White light from the light source 101 is separated by the dichroic mirror 102 into green (hereinafter referred to as G) component light, red (hereinafter referred to as R), and blue (hereinafter referred to as B) component light. The R and B component lights are supplied to the dichroic mirror 103 and separated into R component light and B component light.

  The separated component lights of G, R, and B are supplied to polarization beam splitters 105, 106, and 107, respectively. The component lights of G, R, and B are supplied from the polarization beam splitter to the liquid crystal panel elements 108, 109, and 110, respectively.

  The component light of G, B, and R is controlled in accordance with the input video signal by the respective liquid crystal panel elements, and returns to the polarization beam splitter again, and is supplied to the X prism 111 as projection light depending on the polarization state. And the light component returning to the light source direction.

  The luminance wheel a112 and the luminance wheel b113 have a light transmitting region and a light blocking region, and create a state of transmitting and blocking the projection light by rotating.

  The X prism combines the respective G, R, and B component lights and supplies them to the projection lens 114 as synthesized light.

  The projection lens 114 projects the supplied combined light onto a screen or the like and displays an image.

  Here, the configuration of the luminance wheels a and b will be described in detail.

  FIG. 2 is a plan view of the luminance wheels a and b. As shown in the figure, the region is divided along the circumferential direction. In this embodiment, 25% is a region that blocks light and the remaining 75% is a region that transmits light. Each of the brightness wheels is individually rotated by using an individual driving device such as a motor. By rotating the luminance wheel, an area where the light shielding areas overlap and an area where the light transmission areas overlap are formed by the rotational phases of the luminance wheels a and b. Thereby, the light shielding state and the projection state of the projection light are created, and it is possible to prevent the state where the image is always displayed. Further, by controlling the rotation phase of the luminance wheel, the light shielding ratio can be changed between 25% and 50% as shown in FIG. The rotation phases of the luminance wheels a and b are controlled by processing to be described later. FIG. 3 shows an example in which the light shielding rate is changed between 25% and 50%, but by appropriately setting the number of luminance wheels, the distribution of light shielding regions and light transmitting regions of the luminance wheel, and the rotation phase, A desired light shielding rate change range can be realized.

  The rotational phase control block shown in FIG. 4 will be described in detail.

  The rotation phase control block in this embodiment includes a video signal input unit 401, a luminance signal calculation unit 402, a luminance frame difference histogram detection unit 403, a frame memory a404, a luminance histogram detection unit 405, a rotation phase calculation unit 406, a frame memory b407, The rotation phase control mechanism unit 408 is configured.

  The video signal input from 401 is converted from the color signal format of the video signal input by the luminance signal calculation unit 402 into a luminance signal using matrix calculation. For example, when the input video signal is an R, G, B signal, it is converted into a luminance signal by performing a predetermined matrix operation.

  The video signal converted into the luminance signal is supplied to the luminance frame difference histogram detection unit 403, the frame memory a404, and the luminance histogram detection unit 405. The luminance frame difference histogram detection unit 403 calculates frame difference information from the difference between the luminance signal delayed by one frame period by the frame memory a404 and the luminance signal from the luminance signal extraction unit 402, and detects the histogram from the frame difference information. .

  A luminance histogram detection unit 405 detects a histogram of the luminance signal output from the luminance signal extraction unit 402.

  The rotation phase calculation unit 406 includes a luminance frame difference histogram output from the luminance frame difference histogram detection unit 403, a luminance histogram output from the luminance histogram detection unit 405, and a rotation phase result for an arbitrary frame in the past from the frame memory b407. Thus, the rotational phase is calculated to determine the light shielding rate. As an example, a flowchart is shown in FIG. When the luminance frame difference histogram detection result is distributed more in the smaller frame difference value as shown in FIG. 6a, the still image is more distributed in the larger frame difference value as shown in FIG. 6b. If it is, it is determined as a moving image. In addition, when the detection result of the luminance histogram has a lot of high gradation data distributed as shown in FIG. 7a, it is determined as a bright image, and when it has a large distribution below halftone as shown in FIG. 7b, it is determined as a dark image. . From these two histogram detection results, the rotational phase is calculated to control the light shielding rate.

  When the rotation phase is determined to be a still image, no moving image blur occurs. Therefore, control is performed so that the rotation phase is minimized and the light shielding rate is minimized regardless of the result of the luminance histogram. If it is determined to be a movie, then the result of the luminance histogram is used. When it is determined that the image is dark, the rotation phase is maximum and the shading rate is maximum.When it is determined that the image is bright, the rotation phase is intermediate and the light blocking rate. Is controlled to be intermediate. When the video is determined to be a bright image, by not controlling the light shielding rate to the maximum, it is possible to suppress the occurrence of conspicuous flickering by increasing the light shielding rate especially for a bright image. In this embodiment, the light shading rates are classified into three, but the present invention is not limited to this, and the still image degree for determining how much the still image is determined by performing the frequency distribution data analysis of the luminance frame difference histogram in detail. Similarly, the frequency distribution data analysis of the luminance histogram is performed in detail to calculate a bright video level for determining how bright the video is, and a configuration in which three or more multi-stage shading rates are obtained from these two parameters. You can also take

  In addition, using the rotational phase calculation result for an arbitrary frame in the past, the shading rate set this time is largely changed from the previous time, and the perception that the brightness greatly fluctuates is suppressed. For example, when a still image is displayed and the scene changes, it is determined as a moving image from the luminance frame difference histogram. In this case, when the shading rate is a still image, the minimum shading rate is set, but at the moment when it is determined to be a movie, the shading rate is set large, and the fluctuation range of the shading rate becomes large. Brightness will fluctuate greatly and will be perceived. Therefore, the rotation phase actually set is calculated from the rotation phase calculation result for the past arbitrary frame stored in the frame memory b and the rotation phase calculated this time, and the light shielding rate is determined not to vary greatly. By doing so, it is possible to prevent the brightness from fluctuating greatly. This can be realized by digitizing the rotation phase calculation result and performing an average calculation. As an example, Table 1 shows the rotation phase result with the minimum light shielding rate set to “0”, the rotation phase result with the maximum light shielding rate set to “31”, and reference to the rotation phases for the past four frames. . As shown in Table 1, when the rotational phase result of the past 4 frames is “0” and the current rotational phase result is “31”, the rotational phase result is averaged with the past 4 frames, The rotation phase to be set is set to a light shielding rate equivalent to “6”, and is not a change from “0” to “31” but a change from “0” to “6”. Can do.

The rotation phase calculation result calculated by the rotation phase calculation unit 406 is supplied to the rotation phase control mechanism 408 and also supplied to and saved in the frame memory b407, and is used for the next rotation phase calculation.

  The rotation phase control mechanism 408 controls the rotation phase of the luminance wheels a and b so as to be the rotation phase calculated by the rotation phase calculation unit, thereby controlling the light shielding rate.

  By preparing a plurality of luminance wheels in which the light shielding area and the transmission area are arranged in this way and changing each phase adaptively, the light shielding ratio for shielding the projection light can be changed. it can. As a result, it is possible to adjust the improvement level of moving image blur, and the moving image improvement level can be changed according to the input video signal.

  Next, a second embodiment of the present invention will be described.

  The optical system block diagram in the present embodiment is the same as that in the first embodiment. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  Similar to the rotation phase control block of the first embodiment, the video signal input unit 401, the luminance signal calculation unit 402, the luminance frame difference histogram detection unit 403, the frame memory a404, the luminance histogram detection unit 405, the rotation phase calculation unit 406, the frame A memory b407 and a rotation phase control mechanism unit 408 are provided, and a light source output control unit 801 is added.

  The rotational phase control and light source control block shown in FIG. 8 will be described in detail.

  The light source output control unit 801 controls the light source output in accordance with the light shielding rate determined by the rotational phase. When the light shielding rate by the luminance wheel is controlled to the maximum rotational phase, the light source output control unit 801 controls the light source output to the maximum. . When the light shielding rate is controlled to the lowest rotation phase, the light source output is controlled to be the projection light having the same brightness as the light source output maximum at the maximum light shielding rate. For example, if the light shielding rate when controlled at the maximum rotational phase is set to 50% and the light source output at this time is set to 100%, the brightness of the projection light can be expressed by the product of the light source output and the light shielding rate. Since it is possible, it becomes 50%. Assuming that this is the maximum brightness of the projection light, when the shading rate controlled by the rotation phase subsequently changes to 25%, the brightness of the projection light is set by setting the light source output to 67%. Therefore, the brightness of the projection light can be kept almost constant. This configuration can be realized by using a look-up table that outputs light source output characteristics using the light shielding rate determined from the rotational phase calculation result as a parameter.

  Thus, by controlling the light source output from the light shielding rate determined from the rotation phase calculation result, the brightness of the projection light can be kept constant while improving the motion blur.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

101 Light source 102, 103 Dichroic mirror 104 Mirror 105, 106, 107 Polarizing beam splitter 108, 109, 110 Liquid crystal panel element 111 X prism 112 Luminance wheel a
113 Brightness wheel b
114 Projection lens 401 Video signal input unit 402 Luminance signal calculation unit 403 Luminance frame difference histogram detection unit 404 Frame memory a
405 Luminance histogram detector 406 Rotation phase calculator 407 Frame memory b
408 Rotational phase control mechanism 801 Light source output control

Claims (7)

  Color separation means for splitting light from a light source into a plurality of color components, light modulation means for performing light modulation according to a video signal for each of the plurality of color components, and color synthesis means for combining the light-modulated color component lights A means for shielding the color-combined light and a projection means for projecting the color-combined light, the light-shielding means comprising a plurality of light-shielding means, and the light-shielding ratio of the projection light being variable. A projector device characterized by this.   The light shielding means includes a light transmitting region and a light shielding region, and generates a state of transmitting projection light and a state of shielding light by rotating, and means for controlling a rotation phase when a plurality of the light is used. The projector device according to claim 1, further comprising:   The rotation phase control means includes a luminance signal conversion means, a luminance frame difference histogram detection means, a luminance histogram detection means, a first frame memory, a rotation phase calculation means, and a second frame memory, The projector apparatus according to claim 1, wherein a rotation phase is calculated using a luminance frame difference histogram, the luminance histogram, and a past rotation phase result stored in the second frame memory.   Color separation means for splitting light from a light source into a plurality of color components, light modulation means for performing light modulation according to a video signal for each of the plurality of color components, and color synthesis means for combining the light-modulated color component lights A means for shielding the color-synthesized light, a projection means for projecting the color-synthesized light, and a light source output control means. The light-shielding means comprises a plurality of light-shielding means, and the light shielding ratio of the projection light is A projector apparatus characterized by being changeable and capable of changing a light source output.   The light shielding means includes a light transmitting region and a light shielding region, and generates a state of transmitting projection light and a state of shielding light by rotating, and means for controlling a rotation phase when a plurality of the light is used. The projector device according to claim 4, further comprising:   The rotation phase control means includes a luminance signal conversion means, a luminance frame difference histogram detection means, a luminance histogram detection means, a first frame memory, a rotation phase calculation means, and a second frame memory, 5. The projector device according to claim 4, wherein a rotation phase is calculated using a luminance frame difference histogram, the luminance histogram, and a past rotation phase result stored in the second frame memory. The projector device according to claim 4, wherein the light source output control unit controls a light source output in accordance with a rotation phase calculated by the rotation phase control unit.