JP4371749B2 - Projector and its test pattern detection method - Google Patents

Description

  The present invention relates to a projector and a test pattern detection method thereof, and more particularly to a projector that extracts a test pattern without using an input signal and a test pattern detection method thereof.

  The conventional method for detecting a test pattern in a projector avoids this when a test pattern is used, because the processing becomes complicated if the input signal and the test pattern are mixed in the image sensor. That is, conventionally, only a test pattern is displayed, and the trapezoidal distortion or the like is corrected by photographing the test pattern.

  Test signals are also used in image correction apparatuses that automatically perform various corrections such as convergence, geometric distortion, luminance, and focus of a color television receiver (see Patent Document 1). In addition, a test signal is superimposed on a display screen and then shooting is performed with an image sensor (see Patent Document 1).

JP-A-6-303624 (7th and 8th pages, FIG. 22) JP-A-6-327019 (page 4, FIG. 1)

  The above-described conventional projector and its test pattern detection method cause a complicated process, and according to the devices of Patent Documents 1 and 2, the circuit configuration is complicated and a large-scale device is required. There is.

  An object of the present invention is to provide a projector capable of detecting a test pattern with a simple circuit configuration and a simplified procedure even when a test pattern is used while an input video is displayed, and a test pattern detection method therefor Is to provide.

In order to solve the above-described problems, a projector according to the present invention includes a test pattern generation circuit that generates a test pattern by operating a button, and when a test pattern is generated from the test pattern generation circuit, the projector is superimposed or inverted on a projected image. A projection data output unit for superimposing and outputting, a projection lens for enlarging and projecting the projection video output from the projection data output unit to an external projection target, and a video projected on the projection target A photographing lens and an image sensor for photographing, the projection image data in the projection data output unit is stored, and the first photographed image obtained by superimposing the test pattern obtained through the image sensor and the test
A storage unit for storing a second captured video with a pattern inverted and superimposed, a previous first captured video stored in the storage unit, and an addition based on a video obtained by reversing the luminance level of the second captured video in black and white The projector body includes a calculation unit that performs calculation and extracts the test pattern even when the projection image is displayed, and a test pattern output unit that outputs the test pattern detected by the calculation unit. .

The projector of the present invention includes a focus button, and can perform an autofocus operation based on data output from the test pattern output unit when the button is pressed .

In addition, the projector test pattern detection method of the present invention includes a first video in which a test pattern is superimposed on an input video, and a second video in which the luminance level of only the test pattern in the first video is reversed in black and white. , Each of the first video and the second video displayed on the projection object is shot and stored in a storage unit, and the first video and the second video are shot. The test pattern is extracted by performing an addition operation using an image obtained by reversing the luminance level of the image in black and white .

Further, according to the test pattern detection method for a projector of the present invention, when a projection video is output from the projector main body and displayed, a superimposing display step for superimposing and displaying the test pattern on an input signal to be projected, and a display on the projection target A first storage step for capturing the projected image as a captured image into a storage unit via a photographic lens and an image sensor, and pattern inversion superimposition that inverts only the test pattern in black and white and superimposes it on the input signal A display step, a second storage step of capturing the pattern reversal projection image displayed on the projection object into the storage unit as a pattern reversal captured image via the photographing lens and the image sensor, and the second storage. An image obtained by inverting the brightness level of the pattern-inverted projection image stored in the storage unit in the step, and the first step. Wherein the calculating step for adding the said captured image stored in the flop by the arithmetic unit is characterized by extracting and outputting a test pattern.

  In the test pattern detection method, the projector main body includes an autofocus button and a test pattern generation circuit driven by the autofocus button, and displays the projection object only when the autofocus button is operated. The test pattern can be superimposed on the projected video.

  In addition, the test pattern extracted by adding and calculating the various captured images in the test pattern detection method remains at a level in a screen obtained through the photographing lens, while the test pattern In other cases, the luminance level can be output as being lowered to dark gray.

  The method for detecting a test pattern of a projector according to the present invention has an effect that the test pattern can be detected even when the test pattern is superimposed on an input image when detecting the test pattern of the projector.

  A projector and a test pattern detection method thereof according to the present invention include a projection lens for projecting an image and an image for capturing the projected image in a projector device using a grid display device typified by a liquid crystal panel. It has an element and a photographing lens, and photographs a test pattern projected together with an input image by the image sensor. In particular, when a test pattern is displayed overlaid on an input signal, two types of video images are captured and displayed when the test pattern is displayed normally and when the test pattern is reversed in black and white. Is characterized by efficient extraction.

In short, the first video in which the test pattern is superimposed on the input video and the second video in which the luminance level of only the test pattern is reversed in black and white in the first video are respectively projected and displayed on the projection object. The first video and the second video are each shot and stored in the storage unit, and the addition operation of the video obtained by reversing the luminance level of the video shot of the first video and the video shot of the second video is reversed. By doing so, the test pattern is extracted .

  FIG. 1 is a schematic diagram showing the relationship between a projector body and a projection object for explaining the outline of the present invention. As shown in FIG. 1, the projector in this embodiment includes a projector main body 1 and accessories (not shown), and the projector main body 1 includes a projection lens 2 and a photographing lens 3. The projection lens 2 in the projector main body 1 is a lens that projects an image on a projection object such as a wall 4 by using input video data supplied from the outside or video data stored inside the main body. The photographing lens 3 is a lens for photographing an image projected on a projection body such as the wall 4, and is disposed at a position immediately above the normal projection lens 2. In addition, this imaging lens 3 can be integrated with an imaging element for actual imaging.

  In such a projector, when correcting trapezoidal distortion, focus, or the like of an image projected from the projection lens 2 onto the wall 4, a test pattern is used. Here, the projection pattern 2 is projected onto the wall 4 together with the input image, and the image is captured by the imaging lens 3, whereby the projection state is captured by the projector body 1. That is, this test pattern uses the principle of triangulation using the difference in the positions of the projection lens, the subject, and the image sensor, and can realize the trapezoidal distortion correction and the autofocus function.

FIG. 2 is a main block diagram of the projector main body shown in FIG. As shown in FIG.
The projector body 1 includes operation buttons for various fine adjustments, but here, as an example, a focus button 11 for executing trapezoidal distortion and autofocusing is shown as an example.

  The projector main body 1 includes a test pattern generation circuit 10 that generates a test pattern by the operation of the focus button 11 described above, and a projection that is superimposed on the projected video and output when the test pattern is generated from the test pattern generation circuit 10. A data output unit 5 and a projection lens 2 for projecting the projection video output from the projection data output unit 5 on a projection object such as a wall 4 are provided. When the focus button 11 is not pressed, only the input image is projected onto the projection object such as the wall 4. The projection data output unit 5 includes a D / A converter for converting digital data into an analog signal.

  In addition to the above, the projector main body 1 includes a photographing lens 2 and an image sensor 6 for photographing an image projected on a projection object such as the wall 4, and a projection image output from the projection data output unit 5 described above. In addition to storing data, a storage unit 7 that stores shooting data obtained via the image sensor 6 and an addition operation based on various video data stored in the storage unit 7 display a projected image. Even in this state, a calculation unit 8 for extracting a test pattern and a test pattern output unit 9 for outputting a test pattern detected by the calculation unit 8 are provided. The test pattern extracted by the calculation unit 8 is used for correction of trapezoidal distortion or the like in the projector main body 1 or outside. However, in order to simplify the description, the description of the trapezoidal distortion itself is omitted. The video data supplied from the storage unit 7 to the projection data output unit 5 can also be supplied directly from the outside.

  Hereinafter, a specific procedure of the test pattern detection process will be described with reference to FIGS.

  FIG. 3 is a process step diagram of the projector main body when the test pattern is superimposed in FIGS. 1 and 2. As shown in FIG. 3, in the test pattern extraction process, a projected image is displayed on the wall 4 from the projector body 1. At that time, a superimposed display step S1 for superimposing and displaying a test pattern on the input signal to be projected, and a projection image displayed on the projection object such as the wall 4 through the photographing lens 3 and the imaging element 6, A first storage step S2 to be taken into the storage unit 7 as the photographed video A, a pattern inversion superposition display step S3 in which only the above-described test pattern is inverted in black and superimposed and displayed on the input signal, and a projection object such as the wall 4 A second storage step S4 for fetching the pattern reversal projection video B displayed on the screen into the storage unit 7 as the pattern reversal captured video B via the photographing lens 3 and the image sensor 6, and the storage unit in the second storage step S4. 7 reverses the luminance level of the pattern reversal projection video B stored in the memory 7 and takes it into the storage unit 7, and the captured video A stored in the storage unit 7 and And a calculation step of adding the luminance level inverted image B ′ of the pattern inverted captured image B by the calculating unit 8. These captured images are added by the calculation unit 8 so that only the test pattern is emphasized and output as a test pattern for trapezoidal distortion correction.

  FIG. 4 is a schematic diagram of a captured video screen for more specifically explaining the test pattern extraction step in FIG. As shown in FIG. 4, this schematic diagram shows only the captured images A, B, and B ′, the addition operation, and the final result in the test pattern extraction step described above. That is, the final result shown at the right end is that the test pattern extracted by adding and calculating various photographic images by the calculation unit 8 remains in the screen obtained through the photographic lens 3 as it is, and other than the test pattern Data (video) is output in a state where the luminance level is lowered to dark gray, for example, a luminance level of 25%.

  In short, the test pattern is superimposed on the input signal and displayed, and the captured image is taken as the captured image A. After that, the test pattern obtained by reversing the black and white (intensity level reversal) is displayed superimposed on the input signal, and the image is taken as a captured image B. Further, a captured video B ′ is obtained by reversing the luminance level of the captured video. Finally, when the captured images A and B ′ are added, the test pattern is emphasized and the input signal is removed, as shown at the right end described above.

  In this way, even when a test pattern such as a cross hatch is displayed over the normal video, only the test pattern can always be selectively extracted.

  INDUSTRIAL APPLICABILITY The present invention is used in a conference system apparatus using the Internet or a projector for projection (projection apparatus) inside or outside the company, and in particular, automatically corrects its trapezoidal distortion or performs autofocus (autofocus) adjustment. It can be applied to

It is a schematic diagram showing the relationship between the projector main body and a to-be-projected body for demonstrating the outline | summary of this invention. It is a main block block diagram of the projector main body shown in FIG. FIG. 3 is a process step diagram of the projector main body when a test pattern is superimposed in FIGS. 1 and 2. FIG. 4 is a schematic diagram of a captured video screen for more specifically explaining a test pattern extraction step in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Projector main body 2 Projection lens 3 Shooting lens 5 Projection data output part 6 Imaging element 7 Memory | storage part 8 Calculation part 9 Test pattern output part 10 Test pattern generation circuit 11 Autofocus button S1-S7 Processing step

Claims (5)

A test pattern generation circuit for generating a test pattern by operating a button ;
When a test pattern is generated from the test pattern generation circuit, a projection data output unit that superimposes or inverts and outputs the projection image; and
A projection lens for projecting the projection image output from the projection data output unit on an external projection object;
A photographing lens and an image sensor for photographing an image projected on the projection object;
The projection data output unit stores data of the projection video, and the first captured video on which the test pattern obtained through the imaging element is superimposed and the
A storage unit for storing a second photographed image obtained by inverting and superimposing a test pattern ;
The brightness levels of the first photographed image and the second photographed image stored in the storage unit are set.
An arithmetic unit that performs an addition operation based on a black and white inverted image and extracts the test pattern even when the projection image is displayed;
And a test pattern output unit that outputs the test pattern detected by the arithmetic unit. The first video obtained by superimposing the test pattern on the input video and the second video obtained by reversing the luminance level of only the test pattern in the first video are respectively projected and displayed on the projection object. Each of the first video and the second video is shot and stored in the storage unit,
The projector is characterized in that the test pattern is extracted by performing an addition operation using an image obtained by reversing the luminance level of the captured image of the first image and the captured image of the second image . Test pattern detection method. When outputting and displaying a projected image from the projector body, a superimposed display step for displaying a test pattern superimposed on an input signal to be projected, and a projection lens and an image sensor for displaying the projected image displayed on the projection target A first storage step for capturing the captured image as a captured image in the storage unit;
A pattern reversal superimposing display step for reversing only the test pattern in black and white and superimposing it on the input signal, and a pattern reversal projection image displayed on the projection object through the photographing lens and the image sensor, A second storage step for capturing the inverted photographed image in the storage unit;
Operation for adding the image obtained by inverting the brightness levels of the second of said pattern reversal projected image stored in the storage unit in the storage step, and the captured image stored in the first step in the calculating portion Including steps,
A test pattern detection method for a projector, characterized in that a test pattern is extracted and output. The projector body includes an autofocus button and a test pattern generation circuit driven by the autofocus button, and the projection video displayed on the projection object only when the autofocus button is operated, 4. The test pattern detection method for a projector according to claim 3, wherein the test pattern is superimposed. Test pattern the extraction, while remaining at the same level in the screen obtained through the photographing lens, according to claim 3, wherein other than the test pattern, characterized in that the output in a state where lowering the luminance level to a dark gray Projector test pattern detection method.

Images