JP2002135690A - Projection display device - Google Patents

Abstract

(57) [PROBLEMS] To provide a projection display device for projecting an image on a display device onto a projection surface, wherein a trapezoidal distortion of a projection image on the projection surface is caused by a positional relationship between the projection display device and the projection surface. The characteristic of the correcting means for correcting is as follows. SOLUTION: A first correction amount according to an angle at which an optical axis of a light beam of a projection device and the projection plane obliquely intersects in a vertical direction, and is horizontal according to a vertical line position of video data to be displayed on a display device. First correction data in which the compression / expansion rate of the scanning line in the horizontal scanning direction changes sequentially, and second correction in which the compression / expansion rate of the video data in the vertical scanning direction changes uniformly according to the first correction amount. And a horizontal compression / expansion circuit 2 for changing the horizontal compression / expansion rate based on the first correction data, and a vertical compression / expansion based on the second correction data. The video data that has passed in series with the vertical compression / expansion circuit 3 that changes the rate is displayed on the display device 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display device, and more particularly to a correction means for correcting a trapezoidal distortion of a projected image on a projection surface caused by a positional relationship between the projection display device and the projection surface. It has features.

[0002]

2. Description of the Related Art In recent years, digital still cameras, DVDs,
With the widespread use of digital image and video equipment such as DVC, in order to view these output images on a large screen, images projected on a display device in which pixels are arranged in a dot matrix form are projected by a luminous flux projected from a lens. 2. Description of the Related Art Projection display devices such as LCD projectors that project onto a projection surface are widely used. FIGS. 17A and 17B are diagrams showing the installation relationship between the projection display device and the projection surface in use, where FIG. 17A is a side view of the projection surface as viewed from the side, and FIG. 17B is a plan view of the projection surface as viewed from above. It is. That is, FIG.
This is the case where the optical axis 22 of the light beam emitted from the first lens intersects perpendicularly with the projection surface 23, and the projection image 24 projected on the projection surface 23 is projected and displayed on the display device of the projection display device. In this state, the image signal input to the projection display device 21 has no original distortion.

FIG. 18 is also a side view showing an installation relationship between the projection type display device and the projection surface in a use state. The optical axis 22 and the projection surface 23 coming out of the lens of the projection type display device 21 are vertically inclined by α. It is a case where the projection is performed in a state where
The projected image 24 on 3 is trapezoidally distorted in the horizontal direction, extends in the vertical direction, and the vertical linearity of the image cannot be maintained. Further, FIG. 19 is also a side view showing the installation relationship between the projection display device and the projection surface in use, and the optical axis 22 and the projection surface 23 coming out of the lens of the projection display device 21 are inclined by β in the horizontal direction. This is the case where the projection is performed in the state, and the projection surface 2
The projected image 24 on 3 is trapezoidally distorted in the vertical direction and extends in the horizontal direction, so that the horizontal linearity of the image cannot be maintained.

[0004] As shown in FIGS. 18 and 19, when the positions of the apparatus and the projection surface are not set according to the installation specification conditions,
In order to obtain the aspect ratio and the linearity of the image obtained when the position of the device and the projection surface are set according to the installation specification conditions as shown in FIG. 17, the image on the display device is processed by processing the image on the display device. Correction of linearity and trapezoidal distortion is required.

Conventionally, as a method of processing an image on a display device having a unique number of pixels and projecting and displaying the image, a method as disclosed in Japanese Patent Application Laid-Open No. 4-23979 has been proposed. . FIG. 20 shows a projected image and an image on the display device at that time in the distortion correction method in the conventional projection display device.

FIG. 20A shows a trapezoidal distortion generated when the optical axis 22 and the projection surface 23 from the lens of the projection display device 21 are inclined by α in the vertical direction. FIG. 20B is a side view when the horizontal direction of the input video signal is corrected to be trapezoidal and projected, and FIG. 20B corrects the horizontal direction of the input video signal to be trapezoidal and is projected from the lens via the display device 25. Sometimes the projected image 26 on the display device 25
FIG. 7 is a diagram showing a state in which is corrected to a trapezoid. That is, the projected image 26 displayed on the display device 25 is changed in advance in the horizontal scanning direction in accordance with the vertical position in the vertical scanning direction, thereby changing the compression ratio in the horizontal scanning direction.
The trapezoidal distortion is eliminated by correcting the trapezoid upside down.

[0007]

However, when the conventional distortion correction method shown in FIG. 20 is used for a projection display device, the angle between the optical axis of the projection display device lens and the projection surface becomes smaller. As the size increases, the vertical direction of the projected image appears to extend, and the vertical linearity changes between a long position and a short position due to the optical path difference. An optical axis 22 coming out of a lens of the projection display device 1 as shown in FIG.
And no distortion is taken when the projection plane 23 obliquely intersects in the horizontal direction. Further, when the size of the projected image 26 on the display device 25 is changed, the aspect ratio of the projected image changes according to the size, but there is no measure to cope with this, and the installation of the apparatus is up and down. No countermeasures were taken when projecting in the opposite state.

[0008]

In order to solve the above-mentioned problems, a projection type display device according to the present invention is directed to a projection type display device in which an image projected on a display device in which pixels are arranged in a dot matrix form is projected on a light beam projected from a lens. In a projection display device that projects on a projection surface, a first correction amount instructing unit that outputs a first correction amount according to an angle at which the optical axis of the light beam and the projection surface obliquely cross in the vertical direction, The first correction amount creates first correction data in which the compression / expansion rate of the horizontal scanning line in the horizontal scanning direction sequentially changes in accordance with the vertical line position of the video data of the video, and the first correction A determination circuit for creating second correction data in which a compression / expansion rate of the video data in the vertical scanning direction changes uniformly according to the amount; and a compression / expansion of the video data in a horizontal direction based on the first correction data. And a vertical compression / expansion circuit capable of changing a vertical compression / expansion rate of the video data based on the second correction data. A projection type display device characterized in that the video data that has passed serially through a directional compression / expansion circuit and a vertical compression / expansion circuit is displayed on the display device, and the projection type display device responds to a vertical line position of the video data. The horizontal scanning line sequentially changes the compression / expansion rate in the horizontal scanning direction of the video data according to the angle obliquely intersecting the optical axis of the light beam and the projection surface in the vertical direction, and vertically varies the video data in accordance with the angle. Since the compression / expansion rate in the scanning direction is also changed uniformly, the vertical direction of the projected image expands as the angle between the optical axis and the projection surface increases. It is also something that would appear to be.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, an image projected on a display device having pixels arranged in a dot matrix is projected onto a projection surface by a light beam projected from a lens. In the projection display device, a first correction amount instructing unit that outputs a first correction amount according to an angle at which the optical axis of the light beam and the projection surface obliquely cross in the vertical direction, and the first correction amount The first correction data in which the compression / expansion rate in the horizontal scanning direction of the horizontal scanning line sequentially changes in accordance with the vertical line position of the video data of the video is created, and the video data is generated in accordance with the first correction amount. A determination circuit for generating second correction data in which the compression / expansion rate in the vertical scanning direction uniformly changes, and the video data can change the horizontal compression / expansion rate based on the first correction data. water A directional compression / expansion circuit, and a vertical compression / expansion circuit capable of changing a vertical compression / expansion rate of the video data based on the second correction data, the horizontal compression / expansion circuit and the vertical direction. A projection display device characterized in that the video data that has passed serially through a compression / expansion circuit is projected on the display device, and a horizontal scanning line of the luminous flux according to a vertical line position of the video data. The compression / expansion rate of the video data in the horizontal scanning direction is sequentially changed by the angle at which the optical axis and the projection surface obliquely cross in the vertical direction, and the compression / expansion rate of the video data in the vertical scanning direction is also changed according to the angle. Because it is configured to change uniformly,
As the angle between the optical axis and the projection surface increases, the vertical direction of the projected image does not look elongated.

Next, according to a second aspect of the present invention, there is provided a projection apparatus which projects an image projected on a display device in which pixels are arranged in a dot matrix on a projection surface by a light beam projected from a lens. A first correction amount indicating means for outputting a first correction amount corresponding to an angle at which the optical axis of the light beam and the projection surface obliquely intersect in a vertical direction, and the optical axis of the light beam and the projection A second correction amount instructing means for outputting a second correction amount according to an angle at which the planes cross obliquely in the horizontal direction, and the first correction amount according to a vertical line position of the video data of the video. The first correction data in which the compression / expansion rate of the horizontal scanning line in the horizontal scanning direction sequentially changes, and the compression / expansion rate of each horizontal scanning line in the horizontal scanning direction uniformly changes according to the second correction amount is created. ,
And, the compression / expansion rate in the vertical scanning direction of the video data sequentially changes in accordance with the horizontal scanning position according to the second correction amount, and in the vertical scanning direction of the video data in accordance with the first correction amount. A determination circuit for creating second correction data whose compression / expansion rate changes uniformly; and a horizontal compression / expansion capable of changing a horizontal compression / expansion rate of the video data based on the first correction data. A vertical compression / expansion circuit capable of changing a vertical compression / expansion rate of the video data based on the second correction data, wherein the horizontal compression / expansion circuit and the vertical compression / expansion circuit are provided. Projecting the video data serially passing through the display device on the display device, wherein trapezoidal correction is performed when the optical axis of the display device and the projection surface obliquely cross in the vertical direction. And a means for indicating a trapezoidal correction amount when the optical axis of the display device and the projection plane intersect obliquely in the horizontal direction. Therefore, according to the correction amount obtained from the two types of correction amount indicating means, If the aspect ratio of the image displayed on the display device before correction is 4: 3 regardless of the installation relationship between the projection display device and the projection surface, the aspect ratio of the image on the projection surface is corrected to 4: 3 and corrected. If the aspect ratio of the image previously displayed on the display device is 16: 9, the aspect ratio of the image on the projection surface is corrected to 16: 9,
If the aspect ratio of the image displayed on the display device before the correction is 5: 4, the aspect ratio of the image on the projection surface is 5: 4.
In the past, if the projection was performed in a state where the optical axis emitted from the lens of the device and the projection surface crossed obliquely in the horizontal direction, the image on the projection surface was distorted in a trapezoidal shape in the vertical direction. However, it is possible to correct an image that has been extended in the horizontal direction and the horizontal linearity of the image cannot be maintained.

According to a third aspect of the present invention, in the determination circuit, the compression / expansion rate changes stepwise according to the position of the video data in the horizontal scanning direction according to the first correction amount. 3. The projection type display device according to claim 2, wherein the first correction data is created by performing the correction in the horizontal direction.

According to a fourth aspect of the present invention, in the determination circuit, the compression / expansion rate is determined by the second correction amount in accordance with a position of a horizontal scanning line in a vertical scanning direction of the video data. 3. The projection display device according to claim 2, wherein second correction data that changes in a stepwise manner is created, whereby the linearity in the vertical direction can be corrected. Next, the invention according to claim 5 of the present invention is characterized in that the determining means is configured to determine that the first and second correction data are different from the first and second correction amount instructing means. 3. The projection display device according to claim 2, wherein a compression / expansion ratio of the video data in the horizontal scanning direction and the vertical scanning direction changes uniformly according to the correction amount of the lens. When there is no zoom or when supplementing the zoom amount of the lens zoom, it is possible to replace the lens zoom by reducing the video data output to the display device and reducing the video display area on the display device. .

Next, in the invention according to a sixth aspect of the present invention, the judging means changes the first and second correction data in accordance with an inversion operation of the projected image on the display device. 3. The apparatus according to claim 2, wherein
It is also possible to install the device body upside down by turning the image on the display device upside down.If the projection display device is installed upside down, trapezoidal distortion The correction amount and linearity are changed from the normal correction amount.Images obtained when the positions of the projection display device and the projection surface are set according to the installation specification conditions regardless of the installation conditions of the projection display device Can be obtained in the projected image.

Next, the invention according to claim 7 of the present invention is characterized in that the determining means determines that the first and second images are displayed in accordance with a change in an actual display area of an image projected on the display device. 3. The projection display device according to claim 2, wherein the correction data is changed even if an actual video display area on the display device changes. In addition, better correction can be performed. Next, in the invention according to claim 8 of the present invention, the judgment means changes the first and second correction data in accordance with a change in an actual aspect ratio of an image projected on the display device. 3. The projection type display device according to claim 2, wherein the correction data is automatically changed even if the aspect ratio of the image on the display device is changed, so that better correction is possible. Can be done.

(Embodiment) An embodiment of the present invention described in claims 1 to 8 of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing a basic configuration of a projection display according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an A / D converter, which samples the input analog video signal at a cycle of a sampling clock from a timing signal generator 5 created in synchronization with a synchronization signal of the input analog video signal to be displayed. A / D that quantizes and converts to digital signal
It is a converter. Reference numeral 2 denotes a horizontal compression / expansion circuit, which is composed of a frame memory, a selector, a register, and the like. The input analog video signal is sampled and quantized, and is output from the video data output of the A / D converter 1 and the timing generator 5. The compression / expansion in each horizontal scan of the input video signal is performed based on the vertical and horizontal address information. That is, with respect to the video data from the A / D converter 1 temporarily stored in the frame memory, the horizontal compression / expansion ratio is changed based on the correction data input from the determination circuit 7 so that each horizontal scanning of the input video signal is performed. , The compression / expansion rate can be changed stepwise according to the horizontal line position in the vertical scanning direction depending on the correction data, and the linearity in the horizontal scanning direction is corrected. .

Reference numeral 3 denotes a vertical compression / expansion circuit, which comprises a frame memory, a selector, a register, and the like, and receives input from the output of the horizontal compression / expansion circuit 2 and the vertical and horizontal address information output from the timing generator 5. The signal is compressed and expanded in the vertical direction. At this time, the compression / expansion ratio in the vertical direction is changed based on the correction data input from the determination circuit 7 with respect to the input video data temporarily stored in the frame memory. The linearity in the vertical scanning direction is corrected by changing the compression / expansion rate stepwise according to the pixel position.

Reference numeral 4 denotes a D / A converter, which converts video data for which resolution conversion and trapezoidal distortion have been corrected by the horizontal compression / expansion circuit 2 and the vertical compression / expansion circuit 3 into analog image data. The timing generator 5 includes a PLL circuit having a function of changing the phase and the frequency division ratio of the sampling clock, a counter, and the like. The timing generator 5 supplies the sampling clock to the A / D converter 1 and performs vertical synchronization. A line counter that counts a horizontal synchronization signal reset by a signal, a pixel counter that counts a frequency-divided clock that is reset by a horizontal synchronization signal, and the like. The horizontal compression / expansion circuit 2 and the vertical compression / expansion circuit 3 To supply vertical and horizontal address information.

Reference numeral 6 denotes a display device for displaying an image to be projected, which displays a video signal output from the D / A converter 4 using a display drive signal obtained from the timing generator 5. The video on the display device can be turned upside down by switching the display drive signal. Reference numeral 7 denotes a judgment circuit which is constituted by a microcomputer or the like, and has a built-in relationship between the projection angle and the correction data in advance.
First and second correction amount indicating means 8, 9 stored in the ROM or held as an arithmetic expression and input by the user.
The correction data is created based on the correction amount obtained from. By setting the created correction data in the horizontal compression / expansion circuit 2 and the vertical compression / expansion circuit 3, distortion due to the positional relationship between the projection display device and the projection surface is corrected. Further, the determination circuit 7 reduces the pixel area for actually displaying an image on the display device 6 even if the values of the input correction amounts from the first and second correction amount indicating means 8 and 9 do not change. When the aspect ratio of the image on the display device 6 changes, the correction data changes in a predetermined manner in accordance with the change. Also, the correction amount is configured to change by a predetermined amount when the output video is inverted upside down on the display device.

The first and second correction amount indicating means 8,
Reference numeral 9 denotes a push button or a dial or the like which is input by a user of the projection display device. The first correction amount indicating means 8 is arranged so that the optical axis of the display device and the projection surface are perpendicular to each other at an angle α. The second correction amount instructing means 9 indicates the trapezoidal correction amount according to the angle α when obliquely intersecting, and the optical axis of the display device and the projection surface when obliquely intersecting at an angle β in the horizontal direction. This is a means for instructing a trapezoidal correction amount according to the angle β. In FIG. 1, the horizontal compression / expansion circuit 2 is instructed by a first correction amount instructing means 8 for a correction amount, and when correction data is input from a determination circuit 7 in accordance with the correction amount,
Correct the horizontal direction to trapezoid. When the correction amount is designated by the second correction amount instructing means 9 to the determination circuit 7 and correction data based on the correction amount is set in the horizontal compression / expansion circuit 2 by the determination circuit 7, the horizontal compression / expansion circuit 2 performs a compression operation at the same compression ratio on all horizontal scanning lines of an image according to the correction data. FIG. 2 is an explanatory diagram showing an operation of the horizontal compression / expansion circuit 2 to gradually change the compression / expansion rate according to the horizontal line position in the vertical scanning direction. When the input video signal is output from the A / D converter 1 at 800 pixels in the horizontal scanning direction and 600 lines in the horizontal scanning direction and temporarily stored in the frame memory, the input video signal is instructed by the first correction amount instructing means 8. If the correction data determined by the determination circuit 7 based on a certain correction amount sets the compression ratio for the upper side of the image to 95 times, as shown in FIG.
Pixels are compressed to 760 pixels, and a black (hereinafter, referred to as blanking) area 10 is added to each end by 20 pixels, and displayed at the center of the display area of the display device 6. The compression ratio for other horizontal scanning lines is set to 0.
The horizontal direction of the image is corrected to a trapezoid by sequentially approaching the magnification from 95 to 1 (the compression ratio is 1 at the lower side of the image). As shown in FIG. 2B, the correction data determined by the determination circuit 7 based on a certain correction amount specified by the second correction amount specifying means 9 is 0.
If a 98-fold compression ratio is specified, 800 pixels
Pixels are compressed and a blanking area 10 of 16 pixels is added to the left or right end of the image. In FIG. 2, the blanking area 10 is added to the right end of the image because the upper left end of the display device 6 is used as a reference for starting the image display. At this time, when the horizontal scanning direction is divided into five regions and the compression ratio is changed to correct the horizontal linearity of the image, for example, as shown in FIG. 97 times,
The compression ratio is changed according to the area, such as 0.98 times, 0.99 times, or 1 time. Since the compression operation is performed stepwise while keeping the overall compression ratio of the horizontal scanning line at 0.98, the linearity in the horizontal direction can be corrected. When a correction instruction is issued from both the first and second correction amount instructing means 8 and 9, the result obtained by multiplying the compression rates determined independently as shown in FIG. It will be used in the horizontal compression / expansion circuit 2. FIG.
In the case of dividing into five areas as shown in FIG.
(D) The 784 pixels are divided into five regions, and the compression ratio for the upper side of the image is 0.95 × 0.96 = 0.91 from the left end.
Times, 0.95 x 0.97 = 0.92 times, 95 x 0.98
= 0.93 times, 0. 95 x 0.99 = 0.94 times,
0.95 × 1.00 = 0.95 times is designated. The lower side of the image is 0.96 times and 0.97 times the same compression ratio as in FIG.
Times, 0.98 times, 0. It becomes 99 times and 1 time. The blanking area 10 to be added has a left end of 20 pixels and a right end of 36 pixels when the upper left end of the display device 6 is used as a reference for starting image display.
It becomes a pixel. Here, the color of the blanking area 10 added to the image display area of the display device 6 by the trapezoidal correction is not necessarily limited to black, and the area to be divided is
The number is not limited to five, but can be selected in several stages such as 1, 3, 5,. FIG. 2 is similar to FIG.
In order to explain the operation of the horizontal compression / expansion circuit 2, the vertical compression / expansion circuit 3 is not operated, and the output of the horizontal compression / expansion circuit 2 is a direct D / A converter 4.
There is no problem to think of it as input. In the vertical compression / expansion circuit 3 in FIG. 1, when the correction amount is instructed by the first correction amount instructing means 8 and correction data is input from the judgment circuit 7, the vertical compression / expansion circuit 3 is the same in the vertical direction of the image. The compression operation is performed at a compression ratio of, and compression / expansion is performed stepwise depending on the correction data. When the correction amount is designated by the second correction amount instructing means 9 to the determination circuit 7 and the correction data is set in the vertical compression / expansion circuit 3 by the determination circuit 7, the vertical compression / expansion circuit 3 determines the vertical direction of the image. Correct to trapezoid.

FIG. 3 is an explanatory diagram showing the operation of the vertical compression / expansion circuit 3 for changing the compression / expansion rate stepwise according to the pixel position in the horizontal scanning direction. Now, when the display device 6 has a configuration of 600 pixels vertically and 800 pixels horizontally and the horizontal compression / expansion circuit 2 does not perform the trapezoidal correction operation, the input video signal is 800 pixels in the horizontal scanning direction and the horizontal scanning 600 pixels.
When an input video signal is output from the A / D converter 1 on a line, the output is temporarily stored in the frame memory in the vertical compression / expansion circuit 3 and the correction amount indicated by the second correction amount instructing means 9 is stored in the frame memory. When the correction data determined by the determination circuit 7 on the basis of the compression ratio for the left side of the image is set to 0.95, as shown in FIG.
The image is compressed to 0 pixels, a blanking area 10 of 15 pixels is added, and the image is displayed at the center of the vertical display area of the display device.

The compression ratio of the other pixels in the horizontal scanning direction is also increased from 0.95 times to 1 times toward the right side of the image, so that the vertical direction of the image is corrected to a trapezoid (the compression ratio on the right side of the image is 1 time). . As shown in FIG. 3B, when the correction data determined by the determination circuit 7 based on the correction amount specified by the first correction amount specifying means 8 specifies a compression ratio of 0.98, 600 pixels are set. Compression is performed on 588 pixels, and blanking of 12 pixels is added to the upper or lower end of the image. In FIG. 3, since the image is reduced from the upper side of the image based on the lower end of the display device, blanking is added to the upper end of the image. At this time, when the vertical scanning direction is divided into five regions and the compression ratio is changed to correct the linearity of the image in the vertical direction, as shown in FIG.
The compression ratio is changed according to the area, such as 7 times, 0.98 times, 0.99 times, or 1 time. The compression ratio in the vertical scanning line direction is 0. Since the compression operation is performed step by step for each area while keeping the magnification of 98 times, the linearity in the vertical direction can be corrected. When both the first and second correction amount indicating means 8 and 9 are instructed, a product obtained by multiplying the compression rates determined independently of each other is finally used in the vertical compression / expansion circuit 3.

In the above example, as shown in FIG. 3D, the compression ratio for the left side of the image is 0. 95 × 0.9
6 = 0.91 times, 0.95 × 0.97 = 0.92 times,
0.95 × 0.98 = 0.93 times, 0.95 × 0.99
0.94 times and 0.95 × 1.00 = 0.95 times are designated. The right side of the image has the same compression ratio of 0.96 as in FIG.
Times, 0. 97 times, 0.98 times, 0.99 times, 1 times. Since the added blanking area 10 is reduced from the upper side of the image with reference to the start of video display based on the lower end of the display device, the added blanking area 10 in the vertical direction at the left end of the screen has an upper end of 27 pixels. The lower end is 15 pixels. Here, the color of the blanking added to the image display area of the display device by the trapezoidal correction is not limited to black, and the area to be divided is not limited to five. It is assumed that the stage can be selected. FIG. 3 shows the result of not operating the horizontal compression / expansion circuit 2 in order to explain the operation of the vertical compression / expansion circuit 3. The output of the A / D converter 1 is directly transmitted to the vertical compression / expansion circuit 3. There is no problem assuming that the signal is input and output to the D / A converter 4.

When an image is displayed on the entire image display area of the display device without any instruction from both the correction amount indicating means 8 and 9, the input image signal is compressed and expanded so as to have the same number of pixels as the display area of the display device. Figures 2 and 3 are 600 vertical
The resolution is converted to 800 pixels horizontally.

The horizontal compression / expansion circuit (2) and the vertical compression / expansion circuit (3) can also compress and expand the input video signal to the number of pixels of the display area of the display device or less. The video display start point when the image is displayed can be specified in units of one pixel within the number of pixels in the display area. FIGS. 4 and 5 show diagrams in which an image on the display device is reduced and displayed smaller than the display device image display area. For example, in an area of 600 pixels vertically and 800 pixels horizontally, 4 pixels vertically
In the case where the display start position is 100 pixels vertically and 100 pixels horizontally as shown in FIG. 7, the display device area other than the 400 and 600 image areas to be displayed is blanked. Shall be added.

If the projection display apparatus does not have a lens zoom or compensates for the zoom amount of the lens zoom, the horizontal compression / expansion circuit 2 and the vertical compression / expansion circuit 3 as shown in FIGS. The image data to be output to the display device 6 is reduced, and the image display area on the display device 6 is reduced to replace the lens zoom.

The amount of image reduction can be determined by inputting a numerical value displayed on the screen or a key provided on the projection display device. FIG. 6 is a diagram in which the distortion generated when the optical axis emitted from the lens of the projection display device and the projection surface cross obliquely in the vertical direction at this time is shown in FIG.
Shown in FIGS. 6A and 6B show trapezoidal correction performed on an image displayed smaller and smaller than the display device image display area. FIG. 6A is a side view of the projection surface viewed from the side, and FIG. 6 shows the projected image. Also, vertical 60
16: 9, 5: 4 in the area of 0 pixels and 800 pixels in width
If you want to display video with an aspect ratio of
As shown in (b), blanking 10 is applied to areas other than the video display area.
To correct the aspect ratio. In the case where the installation relationship between the projection display device and the projection surface is not set according to the installation specification conditions for the image corrected as shown in FIG. 7, correction is performed as shown in FIG. : 4 aspect ratio. 7A shows a display device 6 in the case where an image is displayed at an aspect ratio of 16: 9 in a display device region of 600 pixels vertically and 800 pixels horizontally, and FIG. 7B shows a display device region of 600 pixels vertically and 800 pixels horizontally. 5 shows the display device 6 when displaying an image with an aspect ratio of 5: 4. At this time, when trapezoidal correction can be performed for the entire display area including the blanking area 10, it is not necessary to consider a change in the correction amount.

FIG. 8 is a diagram in which the distortion generated when the optical axis emitted from the lens of the projection type display device and the projection surface obliquely cross in the vertical direction is corrected by the correction method according to the present invention. FIG.
(A) shows distortion correction of a projection view, and (b) of FIG.
3 shows distortion correction on the display device. In this figure, the lower position of the image on the display device is fixed and compressed from the upper side in the vertical direction of the screen to the lower side. Conversely, the upper position of the image on the display device is fixed as shown in FIG. May be compressed from the lower side in the vertical direction of the screen to the upper side. FIG. 9A shows distortion correction of a projection view.
(B) shows distortion correction on the display device in (a). FIG. 10 is a projection view when the optical axis emitted from the lens of the projection type display device and the projection surface intersect obliquely in the horizontal direction at an angle β. FIG. 10A shows distortion correction of a projection view,
FIG. 10B shows the distortion correction on the display device in FIG. In this figure, the position on the right side of the image on the display device is fixed and compressed from left to right in the screen vertical direction. Conversely, as shown in FIG. The compression may be performed from the right side to the left side in the direction. FIG. 11A shows the distortion correction of the projection view, and FIG. 11B shows the distortion correction on the display device in FIG.

FIG. 12 shows the correction amount obtained from the first correction amount indicating means 8 in FIG. 1 when the positional relationship between the projection display apparatus and the projection surface shown in FIGS. FIG. 11 is a diagram in which the correction amount obtained from the second correction amount instruction means 9 is input to a determination circuit 7 and correction processing is performed.

FIG. 12A is a diagram showing the distortion correction of the projection view, and FIG. 12B is a diagram showing the distortion correction on the display device and the second correction amount designation by the first correction amount designating means 8 in FIG. FIG. 9C is a diagram showing the distortion correction on the display device by means 9, and FIG. 9C is a diagram showing the distortion correction on the display device in FIG.

As described above, it is possible to obtain the horizontal, vertical linearity, aspect ratio, and the like of an image obtained when the installation specification is satisfied even if the setting relationship between the projection display device and the projection surface is not set according to the installation specification conditions. It is possible.

FIG. 13 is a diagram in which the image on the display device 6 in FIG. 1 is inverted upside down. When the optical axis emitted from the lens of the projection display device and the projection surface obliquely cross in the vertical direction, the image projected from the lens via the display device 6 of FIG. 13A and the projection display device are turned upside down. In the image projected from the lens via the display device 6 shown in FIG. 13B after being set, the distortion of the image projected on the projection surface is different because the angle of the optical axis emitted from the lens is different. Therefore, the determination circuit 7 checks whether the image is inverted upside down on the display device, and when the image is inverted upside down, the correction data for the upside down is used.

FIG. 14 is a flow chart showing the operation of the embodiment in the judgment circuit 7 of FIG. The correction data calculation of FIG. 14 can be operated even by reading data set in the ROM. Further, “whether the operation is a reduction operation” indicates whether or not the lens zoom is compensated by reducing the image display area on the display device.

The first correction amount instructing means 8 in FIG. 1 corrects the distortion generated when the optical axis from the lens of the projection type display device and the projection surface cross obliquely in the vertical direction as shown in FIGS. It is used in the case. Here, the correction amount is expressed as a numerical value. The addition and subtraction of the correction amount can be instructed by the input of the first correction amount instructing means 8. The correction amount when no correction is performed is set to 0, and the correction amount is set to 0. The correction amount can be increased as shown in FIGS. 8 and 9 by increasing the correction amount from 0 to 1, 2,. In this case, the larger the correction amount, the larger the correction amount when the angle α is large.
Further, the first correction amount indicating means 8 changes the correction amount from 0 to-
.. Can be corrected as shown in FIG. In this case, the smaller the correction amount is, the larger the angle α becomes. FIG. 15A illustrates distortion correction of a projection view, and FIG. 15B illustrates distortion correction on the display device 6 in FIG.

The second correction amount indicating means 9 in FIG. 1 is a distortion generated when the optical axis emitted from the lens of the projection type display device and the projection surface cross obliquely in the horizontal direction at an angle β as shown in FIGS. Is used to correct. FIG.
(A) shows the distortion correction of the projection view, and (b) shows the distortion correction on the display device in (a). Here, the correction amount is represented by a numerical value. The addition and subtraction of the correction amount can be instructed by the input of the second correction amount instructing means 9. The correction amount when no correction is performed is set to 0, and the second correction amount is set to 0. The correction amount is set from 0 to 1 by the correction amount instructing means 9.
As the number increases, correction can be made as shown in FIG. In this case, the larger the correction amount is, the larger the angle β becomes. When the correction amount is reduced from 0 to -1, -2... By the second correction amount instruction means 9, correction can be performed as shown in FIG. In this case, as the correction amount becomes smaller,
This is the correction amount when the angle β in FIG. 16 is large.

[0035]

As described above, according to the present invention, according to the vertical line position of the video data, the horizontal scanning line is formed by changing the horizontal angle of the video data by the angle at which the optical axis of the light beam and the projection plane obliquely cross in the vertical direction. Since the compression / expansion rate in the scanning direction is sequentially changed, and the compression / expansion rate in the vertical scanning direction of the video data is also changed uniformly according to the angle, the angle between the optical axis and the projection surface is changed. Does not seem to extend in the vertical direction of the projected image.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main part of a projection display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an image on a display device showing an operation of changing a compression / expansion ratio stepwise according to a horizontal line position in a vertical scanning direction of a horizontal compression / expansion circuit 2 in the embodiment of the present invention.

FIG. 3 is a diagram showing an image on a display device showing an operation of the vertical compression / expansion circuit 3 in the embodiment of the present invention to change the compression / expansion ratio stepwise according to the pixel position in the horizontal scanning direction.

FIG. 4 is a diagram showing an image on a display device reduced and displayed smaller than a display device image display area in the embodiment of the present invention.

FIG. 5 is a diagram showing an image on a display device reduced and displayed smaller than a display device image display area in the embodiment of the present invention.

FIG. 6 is a diagram obtained by correcting a projection view in which an image on a display device is reduced and displayed smaller than a display device image display area in the embodiment of the present invention.

FIG. 7 is a display device diagram when video is displayed at an aspect ratio of 16: 9 and an aspect ratio of 5: 4 in an area of 600 pixels vertically and 800 pixels horizontally according to an embodiment of the present invention.

FIG. 8 is a diagram in which distortion generated when an optical axis emitted from a lens of the projection display apparatus according to the embodiment of the present invention obliquely intersects the projection surface at an angle in the vertical direction.

FIG. 9 is a diagram in which distortion generated when an optical axis emitted from a lens of the projection display apparatus according to the embodiment of the present invention obliquely intersects the projection surface at an angle in the vertical direction.

FIG. 10 is a diagram in which distortion generated when an optical axis of a projection type display device according to an embodiment of the present invention obliquely intersects an optical axis and a projection surface obliquely in a horizontal direction.

FIG. 11 is a diagram in which a distortion generated when an optical axis emitted from a lens of the projection display device according to the embodiment of the present invention obliquely intersects the projection surface in the horizontal direction is corrected.

FIG. 12 is a diagram in which distortion generated when an optical axis emitted from a lens of a projection type display device according to an embodiment of the present invention and a projection surface cross obliquely in the horizontal and vertical directions is corrected.

FIG. 13 is an inverted view of an image on a display device of the projection display device according to the embodiment of the present invention.

FIG. 14 is a flowchart illustrating a correction method of the projection display device according to the embodiment of the present invention.

FIG. 15 is a diagram in which distortion generated when an optical axis emitted from a lens and a projection surface of a projection type display device according to an embodiment of the present invention obliquely intersect in a vertical direction.

FIG. 16 is a diagram in which distortion generated when an optical axis emitted from a lens of the projection display apparatus according to the embodiment of the present invention obliquely intersects the projection surface in the horizontal direction is corrected.

FIG. 17 is a projection view when an optical axis emitted from a lens of a projection display device intersects perpendicularly with a projection surface.

FIG. 18 is a projection view when an optical axis emitted from a lens of a projection type display device and a projection surface obliquely cross in a vertical direction.

FIG. 19 is a projection view when an optical axis emitted from a lens of a projection display device and a projection surface obliquely intersect in a horizontal direction.

FIG. 20 is a diagram in which distortion generated when an optical axis emitted from a lens of a conventional projection display device and a projection surface obliquely cross in a vertical direction is corrected.

[Explanation of symbols]

 Reference Signs List 1 A / D converter 2 Horizontal compression / expansion circuit 3 Vertical compression / expansion circuit 4 D / A converter 5 Timing generator 6 Display device 7 Judgment circuit 8 First correction amount indicating means 9 Second correction amount indicating means 10 Ranking 21 Projection display device 22 Optical axis 23 Projection surface 24 Projected image

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G09G 3/36 G09G 3/36 (72) Inventor Koji Tachikawa 1-8 Koshinmachi, Takamatsu-shi, Kagawa Prefecture Matsushita Hisashi Denko Kogyo Co., Ltd. In-house F term (reference) 5B057 AA20 BA23 CB12 CB16 CC03 CD05 CD12 5C006 AA01 AB01 AF46 AF61 BB11 BF38 EC11 FA05 FA18 FA21 5C058 AA05 BA35 EA00 5C080 AA10 BB05 DD01 EE21 JJ01 JJ07

Claims (8)

[Claims] 1. A projection display apparatus for projecting an image projected on a display device in which pixels are arranged in a dot matrix on a projection surface by a light beam projected from a lens, wherein an optical axis of the light beam and the projection First correction amount instructing means for outputting a first correction amount corresponding to an angle at which the planes cross obliquely in the vertical direction, and the first correction amount according to a vertical line position of the video data of the video. A first correction data in which the compression / expansion rate of the horizontal scanning line in the horizontal scanning direction sequentially changes is created, and the compression / expansion rate of the video data in the vertical scanning direction uniformly changes according to the first correction amount. A determination circuit that creates the second correction data, and a horizontal compression / expansion circuit that can change the horizontal compression / expansion rate of the video data based on the first correction data;
A vertical compression / expansion circuit capable of changing the vertical compression / expansion rate of the video data based on the second correction data, wherein the horizontal compression / expansion circuit and the vertical compression / expansion circuit are connected in series. A projection type display device, wherein the video data that has passed through is projected on the display device. 2. A projection display apparatus for projecting an image projected on a display device in which pixels are arranged in a dot matrix on a projection surface by a light beam projected from a lens, wherein the optical axis of the light beam and the projection First correction amount instructing means for outputting a first correction amount according to an angle at which the plane intersects obliquely in the vertical direction, and a second correction amount instructing means according to an angle at which the optical axis of the light beam and the projection surface obliquely intersect in the horizontal direction. A second correction amount instructing means for outputting a second correction amount, and a compression / expansion rate of a horizontal scanning line in a horizontal scanning direction is sequentially determined according to a vertical line position of the video data of the video by the first correction amount. Changes, and creates first correction data in which the compression / expansion rate of each horizontal scanning line in the horizontal scanning direction changes uniformly according to the second correction amount, and according to the second correction amount. In the vertical scanning direction of video data A determination circuit for generating second correction data in which the compression / expansion rate in the video data sequentially changes according to the horizontal scanning position, and the compression / expansion rate in the vertical scanning direction of the video data uniformly changes in accordance with the first correction amount A horizontal compression / expansion circuit capable of changing a horizontal compression / expansion ratio of the video data based on the first correction data, and a vertical compression / expansion circuit of the video data based on the second correction data. A vertical compression / expansion circuit capable of changing a compression / expansion rate, and displaying the video data that has passed in series through the horizontal compression / expansion circuit and the vertical compression / expansion circuit on the display device. Characteristic projection display device. 3. The method according to claim 1, wherein the determination circuit creates first correction data in which a compression / expansion rate changes stepwise according to a position of the video data in a horizontal scanning direction based on the first correction amount. The projection display device according to claim 2. 4. The determination circuit creates second correction data in which a compression / expansion rate changes stepwise according to a position of a horizontal scanning line in a vertical scanning direction of the video data based on the second correction amount. 3. The projection display device according to claim 2, wherein: 5. The image processing apparatus according to claim 1, wherein the first and second correction data are different from each other in accordance with a correction amount from another instruction means different from the first and second correction amount instruction means. 3. The projection display device according to claim 2, wherein the compression / expansion rates in the horizontal scanning direction and the vertical scanning direction are changed uniformly. 6. The apparatus according to claim 1, wherein said judging means is configured to change said first and second correction data in accordance with an inversion operation of a projected image on said display device. 3. The projection display device according to 2. 7. The method according to claim 1, wherein the determining unit is configured to change the first and second correction data in accordance with a change in an actual display area of an image projected on the display device. 3. The projection display device according to claim 2, wherein: 8. The determining means according to a change in an actual aspect ratio of an image projected on the display device,
3. The projection display device according to claim 2, wherein the first and second correction data are changed.