JP6244542B2 - Projection-type image display device and control method for projection-type image display device - Google Patents

Description

  The present disclosure relates to a projection display apparatus, and more particularly to a projection display apparatus that improves the sense of resolution while maintaining image quality and a control method thereof.

  Conventionally, in order to obtain a high-resolution and high-quality image, a projection-type image display in which a so-called wobbling element is inserted to control the optical path of the image light generated by the display element and change the display position on the projection surface. The device is known.

  On the other hand, there is a known video display device that can provide a higher resolution than the display itself by moving the pixel position on the screen. After the input signal is enlarged, A high-quality video can be displayed by thinning out the output below the resolution of the device (for example, Patent Document 1).

JP 2006-259403 A

  However, when the video signal is enlarged, a high-quality video cannot be provided for a video having a resolution sufficiently higher than the resolution of the apparatus. In particular, when a pixel is selected, if a part or all of the high-frequency component pattern is lost, the quality of the image may be deteriorated.

  The present disclosure is for solving the above-described problems, and provides a projection display apparatus capable of displaying an image with a high resolution feeling while maintaining the quality of an image including a high-frequency component such as text. With the goal.

  A projection display apparatus according to the present disclosure (for example, the projection display apparatus 100) includes an image generation section (for example, the image generation section 20) that generates image light in response to an image input signal, and a projection plane for the image light. A projection optical system (for example, the projection optical system 60) that projects onto the optical path, and an optical path changing unit (for example, the optical path changing unit 80) that is provided on the optical path of the image light and changes the display position on the projection plane of the image light. And a control unit (for example, control unit 70) that generates video light from a part of the video input signal and controls the display position. The gist of the projection type video display apparatus is that the control unit adds information for reducing the influence to the peripheral pixels of the pixel having a great influence of the video deterioration due to the lack of the video input signal.

  According to the present disclosure, it is possible to display an image having a high resolution feeling while maintaining the quality of an image including a high frequency component.

  In the projection display apparatus described above, the control unit extracts target pixels that are greatly affected by image degradation due to missing part of the image input signal, and information that reduces the influence among peripheral pixels of the target pixels. It is preferable to include a determination unit (for example, determination unit 173) that determines an additional pixel to be added, and an addition unit (for example, addition unit 174) that adds information to the additional pixel.

  Further, in the above projection display apparatus, the control unit calculates a difference from the signal value of the peripheral pixel for each pixel, and when the difference between the three or more peripheral pixels is larger than a predetermined threshold, It may be determined that the pixel is greatly affected by deterioration.

  A control method for a projection display apparatus according to the present disclosure includes an image generation unit that generates image light according to an image input signal, a projection optical system that projects image light onto a projection surface, and an optical path of the image light. An optical path changing unit that changes a display position of the image light on the projection surface, and a control unit that controls the image generating unit and the optical path changing unit, and generates the image light from a part of the video input signal. At the same time, the display position is controlled. In this control method, a first step of extracting a target pixel having a large influence of video deterioration due to a lack of a video input signal, and a pixel to be added to which information for reducing the influence is added among peripheral pixels of the target pixel. The gist is to include a second step of determining and a third step of adding information to the added pixel.

  According to the present disclosure, it is possible to provide a projection display apparatus capable of displaying an image having a high resolution feeling while maintaining the image quality.

1 is an external perspective view of a projection display apparatus according to the present disclosure. It is a block diagram which shows the structure of the projection type video display apparatus concerning this indication. It is a schematic diagram explaining the optical structure of the projection type video display apparatus concerning this indication. It is a schematic diagram which shows the optical structure from the image generation part which concerns on this indication to a projection optical system. It is a perspective view explaining the composition of the glass unit concerning this indication. It is a side view explaining the change of the state of the glass unit concerning this indication. It is a block diagram which shows the structure of the control part which concerns on this indication. It is explanatory drawing which shows the relationship between a video input signal and a video output signal in case a video input signal and a display element have the same resolution. It is explanatory drawing which shows the relationship between a video input signal and a video output signal in case a video input signal is 4 times the resolution of a display element. It is explanatory drawing which shows the relationship between a video input signal and a video output signal in case a video input signal is 4 times the resolution of a display element. It is explanatory drawing which shows the relationship of the display position on the screen of a some sub-frame when projecting via an optical path change part. It is explanatory drawing explaining the subject of the image | video containing the high frequency component which concerns on this indication. It is a block diagram which shows the structure of the video signal generation part which concerns on this indication. It is a flowchart explaining the process with respect to the high frequency component which concerns on this indication.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

The applicant provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and is not intended to limit the subject matter described in the claims. Absent.
(Configuration of projection display device)
The configuration of the projection display apparatus 100 will be described with reference to FIGS. FIG. 1 is an external perspective view of the projection display apparatus 100. As shown in FIG. 1, the projection display apparatus 100 projects image light generated according to an image input signal onto a screen 500.

  FIG. 2 is a block diagram illustrating a configuration of the projection display apparatus 100. The projection display apparatus 100 includes a light source unit 10, a video generation unit 20 that generates video light in response to a video input signal, a light guide optical system 50 that guides light from the light source unit 10 to the video generation unit 20, and It has a projection optical system 60 that projects the generated image light onto the screen 500, and a control unit 70 that controls the light source unit 10, the image generation unit 20, and the like.

Although details will be described later, the projection display apparatus 100 further includes an optical path changing unit 80 for shifting the display position of the image light generated by the image generation unit 20 on the screen 500 within a range of the pixel pitch or less. Prepare. The projection display apparatus 100 displays the projection display by shifting the display position of the image light generated by the image generation section 20 on the screen 500 by, for example, 1/2 pixel by the optical path changing section 80. The apparatus 100 can provide an image with a high resolution.
(Optical configuration of the projection display)
The optical configuration of the projection display apparatus 100 will be described with reference to FIG. FIG. 3 is a schematic diagram showing an optical configuration of the projection display apparatus 100.

  The white light emitted from the light source unit 10 enters the lens 52 and is collected near the incident surface of the rod 54. The light incident on the rod 54 is reflected a plurality of times inside the rod, and is emitted with the light intensity distribution substantially uniform. The light emitted from the rod 54 is collected by the lens 56. The lens 56 is a relay lens that forms an image of the exit surface of the rod 54 on a DMD described later. After being reflected by the mirror 58, the light enters the total reflection prism 24 through the lens 22. The lens 22 is a lens that collects incident light substantially in parallel.

  The total reflection prism 24 is composed of two prisms, and a thin air layer 26 is interposed between adjacent surfaces of the prisms. The air layer 26 totally reflects light incident at an angle greater than the critical angle. The light that has entered the total reflection prism 24 via the lens 22 is reflected by the total reflection surface and enters the color prism 28.

  The color prism 28 includes three prisms, and a blue reflecting dichroic film 30 and a red reflecting dichroic film 32 are formed on the adjacent surfaces of the prisms. The light that has entered the color prism 28 is separated into blue, red, and green color light by the blue reflecting dichroic film 30 and the red reflecting dichroic film 32, and is incident on DMDs 34, 36, and 38, respectively. DMDs 34, 36, and 38 deflect the micromirrors into light incident on the projection lens constituting the projection optical system 60 and light traveling outside the effective projection lens in accordance with the video input signal.

  The light reflected by the DMDs 34, 36 and 38 is transmitted through the color prism 28 again. In the process of passing through the color prism 28, the separated blue, red, and green color lights are combined and enter the total reflection prism 24. Since the light incident on the total reflection prism 24 is incident on the air layer 26 at a critical angle or less, it is transmitted and incident on the projection optical system 60. In this way, the image light formed by the DMDs 34, 36, and 38 is projected on the screen.

Since the image generation unit 20 uses the DMDs 34, 36, and 38, the projection display apparatus 100 having higher light resistance and heat resistance than the liquid crystal panel can be configured. Further, since three DMDs are used, color reproduction is good and a bright and high-definition projected image can be obtained.
(Configuration of optical path changing unit)
The configuration of the optical path changing unit 80 will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating an optical configuration from the image generation unit 20 to the projection optical system 60.

  The optical path changing unit 80 includes a glass plate 82 that refracts the optical path of the video light from the video generation unit 20 using refraction, and a piezoelectric element 84 that changes the arrangement angle of the glass plate 82. The piezoelectric element 84 is connected to a piezoelectric element driving unit 72 that supplies electric power to the piezoelectric element 84 and controls expansion and contraction of the piezoelectric element 84.

  The piezoelectric element 84 expands when a predetermined voltage is applied, and contacts the glass plate 82 (glass frame 181). The glass plate 82 pressed from the piezoelectric element 84 changes its arrangement angle about an axis orthogonal to the optical axis of the image light, and the incident angle of the image light incident on the glass plate 82 changes. As a result, the traveling direction of the image light changes slightly, and the display position of the image light on the screen 500 moves.

  The structure of the glass unit 180 including the glass plate 82 will be described with reference to FIG. FIG. 5 is a perspective view showing the configuration of the glass unit 180.

  The glass unit 180 has a glass frame 181 that holds the outer periphery of the glass plate 82. Plate springs 182 and 183 are provided on the surface of the glass frame 181 on the projection optical system 60 side. That is, the leaf springs 182 and 183 are arranged in a direction parallel to the optical axis of the projection optical system 60 with respect to the glass frame 181. The glass unit 180 is supported on the supports 185 and 186 built on the base 184 via leaf springs 182 and 183.

  The piezoelectric element 84 is an element whose length varies when a voltage is applied. The piezoelectric element 84 is fixed to the support column 185 side and disposed so as to be in contact with the glass frame 181. That is, the piezoelectric element 84 is disposed in a direction parallel to the optical axis of the projection optical system 60 with respect to the glass frame 181. A piezoelectric element driving unit 72 is connected to the piezoelectric element 84, and when applied from the piezoelectric element driving unit 72, the piezoelectric element 84 expands. The spring 187 is inserted between the glass frame 181 and the support column 185, and both ends thereof are fixed to the glass frame 181 and the support column 185, respectively. The spring 187 applies a force so that the glass frame 181 and the support column 185 attract each other.

  The leaf springs 182 and 183 are attached perpendicular to the glass plate 82 (parallel to the optical axis of the projection optical system 60). The leaf springs 182 and 183 are preferably attached so that the glass plate 82 reciprocates around the perpendicular to the optical axis of the projection optical system 60. The support columns 185 and 186 are provided in parallel to the glass plate 82 and support the leaf springs 182 and 183 at the ends. The column 185 also supports the piezoelectric element 84 and the spring 187.

  6A is a side view when the glass unit 180 (optical path changing unit 80) is in the reference state, and FIG. 6B is an optical path of video light using the refractive index of the glass plate 82. FIG. It is a side view of the state which shifted (solid line arrow in a figure).

  When a predetermined voltage is applied to the piezoelectric element 84, the piezoelectric element 84 expands and pushes the glass frame 181 in the counterclockwise direction via the hemispherical contact portion 188. As a result, the leaf spring 182 (183) warps and the spring 187 is stretched. On the other hand, when the voltage applied to the piezoelectric element 84 is released, the piezoelectric element 84 contracts. As a result, the glass frame 181 is pulled back in the clockwise direction by the restoring force of the leaf spring 182 (183) and the spring 187, and returns to the reference state as shown in FIG.

As shown in FIG. 6, the plate spring 182, the piezoelectric element 84, and the spring 187 supported by the support column 185 are configured such that the glass plate 82 is optical axis (dotted line) of the projection optical system 60 according to the expansion and contraction of the piezoelectric element 84. It may be attached so as to perform a reciprocating rotational movement at a minute angle around the perpendicular to the center.
(Operation of control unit)
Control by the control unit 70 will be described with reference to FIGS. FIG. 7 is a block diagram illustrating the configuration of the control unit 70. The control unit 70 includes a video signal generation unit 74, a display element driving unit 76, and a piezoelectric element driving unit 72.

  The video input signal input to the control unit 70 is converted into a video output signal to be output to the DMDs 34, 36, 38 in the video signal generation unit 74 and is synchronized with the video light generated by the DMDs 34, 36, 38. Is converted into a sync signal for That is, the video signal generation unit 74 generates a video output signal and a synchronization signal based on the video input signal.

  As shown in FIG. 8, when a video input signal having the same resolution as that of the DMDs 34, 36, and 38 is input, the video signal generation unit 74 outputs video input signals corresponding to the pixels of the DMDs 34, 36, and 38. The video output signal is output as it is to the display element driving unit 76. When a video input signal having a resolution four times the resolution of the DMDs 34, 36, and 38 is input, the video signal generation unit 74 normally performs interpolated pixel signals (four pixel values) from four 2 × 2 signals. (Average value) is calculated and output as a video output signal to each pixel of the DMDs 34, 36, 38, or, for example, as shown in FIG. Are output to the display element driving unit 76 as video output signals.

  When the optical path changing unit 80 is driven to display a double-density video having the resolution of the DMDs 34, 36, and 38, the video signal generation unit 74 outputs 2 video input signals for one frame (for example, the Nth frame). Divide in time into two subframes. Specifically, as shown in FIG. 10, for example, out of four 2 × 2 signals, the upper left signal (the signal with a circle) is the first subframe, and the lower right signal (the Δ is added). Are output to the display element driving unit 76 in this order as video output signals of the second subframe. On the other hand, to the piezoelectric element driving unit 72, the timing at which the first subframe and the second subframe are switched in the DMDs 34, 36, and 38, and the optical path changing unit 80 shift the display position on the screen 500 (the optical path of the image light is changed). Output the synchronization signal so that the timing matches.

  As shown in FIG. 11, the optical path changing unit 80 projects image light at a position indicated by a dotted line on the screen 500 while displaying the image of the first subframe on the DMDs 34, 36, and 38. 38, while the second sub-frame image is being displayed, the optical path is projected so that the image light is projected at a position indicated by a solid line on the screen 500, specifically, at a position moved by 1/2 pixel in both the vertical and horizontal directions. To change.

As a result, on the screen 500, an image having the same number of pixels as the number of pixels of the image input signal is displayed in both the horizontal and vertical directions. In addition, it is possible to match the pixel position of the original video input signal, and to display a video with a sense of resolution that is twice the resolution of the DMDs 34, 36, and 38.
(Operation of video signal generator)
Here, the upper right signal and the lower left signal (signals without ◯ or Δ) in the video input signal of FIG. 10 are not assigned to any subframe. That is, these video signals are not displayed and are lost. When a fine pattern is included in the input video, there is a possibility that a desired video cannot be displayed due to a lack of a signal.

  For example, as shown in FIG. 12, the case where the text “y” is included in the video input signal will be described (FIG. 12A). As described above, the control unit 70 sets the upper left signal to the first subframe and the lower right signal to the second subframe (for example, FIG. 12B) among the four 2 × 2 signals. As a video output signal, the image signal is output to the display element driving unit 76, and the optical path changing unit 80 outputs a synchronization signal to the piezoelectric element driving unit 72 so that the display position on the screen 500 is shifted by 1/2 pixel in both vertical and horizontal directions. . Therefore, the text “y” displayed on the screen 500 does not maintain the shape of “y” and cannot be recognized (FIG. 12C).

  Therefore, in order to solve the above problem, the video signal generation unit 74 of the present embodiment determines a video signal. FIG. 13 is a block diagram illustrating the configuration within the video signal generation unit 74.

  As shown in FIG. 13, the video input signal is first received by the receiving unit 171 in the video signal generating unit 74. The receiving unit 171 divides the input video input signal into large blocks (for example, 12 blocks of 3 × 4), and analyzes the frequency component for each block. When the frequency is lower than a predetermined threshold, the video input signal of the block is sent as it is to the generation unit 172 that generates the video output signals of the first subframe and the second subframe. On the other hand, when the frequency is equal to or higher than a predetermined threshold, the video input signal of the block is sent to the determination unit 173 that determines a pixel that affects the video. Although details will be described later, the addition unit 174 subsequent to the determination unit 173 adds information for reducing the influence of the signal loss to the video input signals of the peripheral pixels of the pixels determined by the determination unit 173.

The video input signal processed by the adding unit 174 is combined with the video input signal sent from the receiving unit 171 as it is, and the generating unit 172 combines the first subframe and the first subframe from the combined video input signal. A video output signal of 2 subframes is generated.
(High-frequency component processing)
Processing of the video input signal for the block whose frequency component is determined to be high by the reception unit 171 will be described with reference to FIG. FIG. 14 is a flowchart of the video input signal processing in the determination unit 173 and the addition unit 174.

  In the video input signal sent to the determination unit 173, a difference from the signal value of the peripheral pixel is calculated for each pixel, and a target pixel whose shape may affect maintenance due to lack of the signal is extracted. Specifically, as shown in Expressions 1, 6, 8, 10, and 12, a pixel having a value sufficiently larger (smaller) than the signal values of three or more neighboring pixels is extracted as a target pixel.

  That is, when the signal value of the pixel to be determined is close to the signal value of any one of the adjacent pixels on the top, bottom, left, and right of the pixel, when the images of the first subframe and the second subframe overlap, There is a possibility that an adjacent pixel compensates the pixel to be determined. On the other hand, when the signal value of the pixel to be determined is a value that is not close to the signal value of the pixel adjacent to the top, bottom, left, and right of the pixel, even if the images of the first subframe and the second subframe overlap, This is because the missing pixel to be determined is not compensated.

  First, as shown in Expression 1, a pixel having a value sufficiently larger (smaller) than the signal values of surrounding four pixels is extracted as a target pixel (S11).

Here, V ₀ is the signal value of the pixel to be judged, V _u is the signal value of the pixel above the pixel to be judged, V _d is the signal value of the pixel below the pixel to be judged, and V _l is the left of the pixel to be judged. signal value of the pixel, V _r is the signal value of the right pixel of the determination pixel, Th is a threshold. In the present embodiment, the threshold value Th is set to 50. The signal value V is actually calculated for each of RGB, and if any one of the colors satisfies Expression 1, it is determined that the pixel is a target pixel.

  For the pixel determined to be the target pixel in step 11 (the pixel satisfying the expression 1), information for reducing the influence of the signal omission on the video input signal of any of the surrounding pixels Is to be added. Specifically, as shown in Expressions 2 to 5, the pixel to be added to which information is added is specified from the relationship with the pixel that is oblique to the target pixel (S21 to S23).

Here, V _ru is the signal value of the upper right pixel of the pixel to be determined, V _rd is the signal value of the lower right pixel of the pixel to be determined, V _lu is the signal value of the upper left pixel of the pixel to be determined, and V _ld is the signal value of V _d This is the signal value of the lower left pixel of the determination pixel.

  When Expression 2 is satisfied, it is determined that the upper left pixel is closer to (or equal to) the target pixel signal value than the lower right pixel, and the upper right pixel is closer to (or equal to) the target pixel signal value than the lower left pixel. Show. That is, the upper left pixel and the upper right pixel are likely to be part of a pixel group that forms some shape together with the target pixel.

  Therefore, when Expression 2 is satisfied (S21: YES), the upper pixel that is close to both the upper left pixel and the upper right pixel is set as a pixel to be added, and information is added to the pixel above the target pixel by the adding unit 174. (S31).

  When Expression 3 is satisfied, it indicates that the lower right pixel is closer to the target pixel signal value than the upper left pixel, and the upper right pixel is closer to (or equal to) the target pixel signal value. That is, the lower right pixel and the upper right pixel are likely to be part of a pixel group that forms some shape together with the target pixel.

  Therefore, when Expression 3 is satisfied (S22: YES), the right pixel close to both the lower right pixel and the upper right pixel is set as a pixel to be added, and information is added to the right pixel of the target pixel by the adding unit 174. (S32).

  When Expression 4 is satisfied, this indicates that the upper left pixel is closer to (or equal to) the target pixel signal value than the lower right pixel, and the lower left pixel is closer to the target pixel signal value than the upper right pixel. That is, the upper left pixel and the lower left pixel are likely to be part of a pixel group that forms some shape with the target pixel.

  Therefore, when Expression 4 is satisfied (S23: YES), the left pixel close to both the upper left pixel and the lower left pixel is set as a pixel to be added, and information is added to the left pixel of the target pixel by the adding unit 174. (S33).

  When Expression 5 is satisfied, it indicates that the lower right pixel from the upper left pixel is closer to the signal value of the target pixel, and the lower left pixel from the upper right pixel is closer to the signal value of the target pixel. That is, the lower right pixel and the lower left pixel are likely to be part of a pixel group that forms some shape with the target pixel.

  Therefore, when Expression 5 is satisfied, a lower pixel close to both the lower right pixel and the lower left pixel is set as a pixel to be added. However, a pixel that satisfies the condition of Expression 1 and does not satisfy the conditions of Expressions 2 to 4 inevitably satisfies Expression 5. Therefore, when NO is determined in all of Steps 21 to 23 (S23: NO) The lower pixel is set as a pixel to be added, and information is added to the pixel below the target pixel by the adding unit 174 (S34).

  Next, as shown in Expressions 6 to 13, no compensation is made among pixels having a value sufficiently larger (smaller) than the signal values of the three pixels around the pixel to be judged (any of S12 to S15 is YES). Pixels having peripheral pixels (S24 to S27: YES) are extracted as target pixels.

  Specifically, when Expression 6 is satisfied, it is indicated that the pixel to be determined has a small difference from the upper pixel and a large difference in signal value from the lower, left, and right pixels. In addition, when Expression 7 is satisfied, the pixel to be determined is compensated by the upper pixel, but the signal value of the lower right pixel or the lower left pixel is close to the pixel to be determined and is not compensated by the lower pixel. May affect shape.

  Therefore, when both the conditions of Expressions 6 and 7 are satisfied (S12: YES and S24: YES), the lower pixel is set as a pixel to be added, and information is added to the pixel below the target pixel by the adding unit 174 (S35). . On the other hand, when Expression 7 is not satisfied (S24: NO), it is not necessary to add information because it is compensated by surrounding pixels.

  When Expression 8 is satisfied, the determination target pixel has a small difference from the lower pixel, and a large signal value difference from the upper, left, and right pixels. In addition, when Expression 9 is satisfied, the pixel to be determined is compensated by the lower pixel. However, since the signal value of the upper right pixel or the upper left pixel is close to the pixel to be determined, May be affected.

  Therefore, when both the conditions of Expressions 8 and 9 are satisfied (S13: YES and S25: YES), the upper pixel is set as a pixel to be added, and information is added to the pixel above the target pixel by the adding unit 174 (S36). . On the other hand, when Expression 9 is not satisfied (S25: NO), it is compensated by the surrounding pixels, so there is no need to add information.

  When Expression 10 is satisfied, it indicates that the pixel to be determined has a small difference from the left pixel and a large signal value difference from the upper, lower, and right pixels. In addition, if the expression 11 is satisfied, the pixel to be determined is compensated by the left pixel, but the signal value of the upper right pixel or the lower right pixel is close to the pixel to be determined, and thus is not compensated by the right pixel. May affect shape.

  Therefore, when both the conditions of Expressions 10 and 11 are satisfied (S14: YES and S26: YES), the right pixel is set as a pixel to be added, and information is added to the right pixel of the target pixel by the adding unit 174 (S37). . On the other hand, when Expression 11 is not satisfied (S26: NO), since it is compensated by the surrounding pixels, it is not necessary to add information.

  When Expression 12 is satisfied, it indicates that the pixel to be determined has a small difference from the right pixel and a large signal value difference from the upper, lower, and left pixels. In addition, when Expression 13 is satisfied, the pixel to be determined is compensated by the right pixel, but the shape of the pixel that is not compensated by the left pixel because the upper left pixel or the lower left pixel has a signal value close to the pixel to be determined. May be affected.

Therefore, when both the conditions of Expressions 12 and 13 are satisfied (S15: YES and S27: YES), the left pixel is set as a pixel to be added, and information is added to the left pixel of the target pixel by the adding unit 174 (S38). . On the other hand, when Expression 12 is not satisfied (S15: NO), it is not a target pixel, so it is not necessary to add information. When Expression 13 is not satisfied (S27: NO), compensation is performed by surrounding pixels. There is no need to add information.
(Additional information to the pixel to be added)
Information added to the pixel to be added is added to the pixel to be added by the adding unit 174 for the video input signal that is extracted as the target pixel and the pixel to be added is specified by the above-described processing. Specifically, the signal value of the added pixel is set to the same value as the signal value of the target pixel. Here, the signal value V is calculated for each of RGB, and if any one of the colors satisfies the condition, it is determined that the pixel is a target pixel. However, the information to be added is the same as the signal value of the target pixel in all of RGB. Value. This is to prevent the color balance from being lost by converting only the colors that satisfy the conditions.

  In order to suppress inconvenience due to chain reaction, the determination unit 173 performs determination based on the signal value of the original video input signal, and after specifying the pixel to be added and information (signal value) to be added are determined, Note that information is added at 174. Further, when information is added more than once in the same pixel, it is preferable to set so that the subsequent processing is prioritized.

The information to be added may use an average value of the signal value of the target pixel and the original signal value of the added pixel, and the signal value of any pixel (for example, the original signal value of the added pixel) You may use the weight average value which weighted to.
[Other Embodiments]
As described above, the first embodiment has been described as an example of the implementation in the present disclosure. However, the present disclosure is not limited to this, and can also be applied to embodiments in which changes, replacements, additions, omissions, and the like have been made as appropriate.

  Although the light source unit 10 is not particularly described in the above-described embodiment, a lamp light source or a solid light source, in particular, a light source that combines a laser light source and a phosphor can be used. Although the video generation unit 20 has been described with the configuration using three DMDs, the present invention is not limited to this, and the configuration using one DMD or a configuration using transmissive and reflective liquid crystal display elements as display elements is also possible. Can be implemented.

  In the above-described embodiment, the operation of the optical path changing unit at double density has been described using the upper left signal and the lower right signal. However, the present invention is not limited to this, for example, the upper right signal and The signal on the lower left may be used. In this case, the direction in which the optical path changing unit changes the optical path of the image light is also configured so that the display position of the image light moves between the upper right and the lower left in accordance with the position of the signal.

  In the above-described embodiment, the generation of the sub-frame video signal in the video signal generation unit has been described with the upper left signal as the first sub-frame. However, the present invention is not limited to this. Signals at other positions may be set as the first subframe, or an interpolation signal may be generated and set as the first subframe.

  In the above-described embodiment, the piezoelectric element is used as the drive member that vibrates the optical path changing unit 80. However, the present invention is not limited to this, and a voice coil motor or the like can also be used. The optical path changing unit 80 is disposed between the image generation unit 20 and the projection optical system 60, but may be disposed between the image generation unit 20 and the screen 500, for example, between lenses in the projection optical system 60. May be inserted.

In the embodiment described above, the value of the threshold T _h was 50, but is not limited thereto. However, when the value of the threshold T _h is too small, erroneous pixels is increased is determined as a target pixel, even if the value is too large threshold T _h, the pixel is not determined as the target pixel is increased, any failure Arise. Empirically, the threshold T _h is the maximum signal value at 255 may be considered 30-100 desirable.

  Moreover, you may add on condition that the difference of the pixel value of adjacent pixels is small about several adjacent pixels with a large difference of a signal value with a target pixel. This makes it clearer that the plurality of adjacent pixels are part of the background image and the target pixel is part of the pattern.

  As described above, the embodiment considered as the best mode and the other embodiments are provided by the attached drawings and the detailed description. These are provided to those skilled in the art to illustrate the claimed subject matter by reference to specific embodiments. Therefore, various modifications, replacements, additions, omissions, and the like can be made to the above-described embodiments within the scope of the claims or an equivalent scope thereof.

  The present disclosure can be applied to a projection display apparatus such as a projector.

DESCRIPTION OF SYMBOLS 10 Light source part 20 Image | video production | generation part 22 Lens 24 Total reflection prism 26 Air layer 28 Color prism 30, 32 Dichroic film | membrane 34, 36, 38 DMD
DESCRIPTION OF SYMBOLS 50 Light guide optical system 52, 56 Lens 54 Rod 58 Mirror 60 Projection optical system 70 Control part 72 Piezoelectric element drive part 74 Image | video signal generation part 76 Display element drive part 80 Optical path change part 82 Glass plate 84 Piezoelectric element 100 Projection type image display Device 171 Reception unit 172 Generation unit 173 Determination unit 174 Addition unit 180 Glass unit 181 Glass frame 182, 183 Leaf spring 184 Base 185, 186 Post 187 Spring 500 Screen

Claims (3)

A generation unit that generates a subframe including a part of pixel signals of a video input signal;
A display element having pixels to which the pixel signals of the sub-frame generated by the generation unit are assigned, and generating video light according to the pixel signals;
A projection optical system that projects the image light generated by the display element onto a projection surface;
An optical path changing unit that is provided on the optical path of the image light and changes a display position on the projection plane of the image light;
A control unit for controlling the display position of the image light,
The controller is
The difference between signal values of peripheral pixels for each pixel is calculated, and when the difference between three or more peripheral pixels is larger than a predetermined threshold , the shape of the display image by the display element is not maintained and cannot be recognized A projection-type image display apparatus that changes a signal value of a pixel that is determined to be affected so as to reduce the influence. The projection display apparatus according to claim 1, wherein
The controller is
The difference between signal values of peripheral pixels for each pixel is calculated, and when the difference between three or more peripheral pixels is larger than a predetermined threshold , the shape of the display image by the display element is not maintained and cannot be recognized A determination unit that extracts a target pixel that is determined to be received and determines a pixel to be added to which information that changes a signal value of the pixel is added so as to reduce the influence among peripheral pixels of the target pixel; ,
An adding unit for adding the information to the pixel to be added;
A projection display apparatus comprising: A generation unit that generates a subframe including a part of pixel signals of a video input signal;
A display element having pixels to which the pixel signals of the sub-frame generated by the generation unit are assigned, and generating video light according to the pixel signals;
A projection optical system that projects the image light generated by the display element onto a projection surface;
An optical path changing unit that is provided on the optical path of the image light and changes a display position on the projection plane of the image light;
A control unit for controlling the display position of the image light,
In a control method of a projection display apparatus that generates the image light from a part of the image input signal and controls the display position,
The difference between signal values of peripheral pixels for each pixel is calculated, and when the difference between three or more peripheral pixels is larger than a predetermined threshold , the shape of the display image by the display element is not maintained and cannot be recognized A first step of extracting target pixels determined to be received;
A second step of determining a pixel to be added to which information to change the signal value of the pixel so as to reduce the influence among peripheral pixels of the target pixel;
A third step of adding the information to the pixel to be added;
A control method for a projection display apparatus.

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