JP2005148157A - Projection type display device and automatic focusing method for projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize accurate automatic focusing by automatically performing the focusing of both the camera lens of a sensor camera and a projection lens. <P>SOLUTION: A test pattern formed by a pattern forming part 20 is projected to a screen 2 by the projection lens 12 and image-picked up by the sensor camera 14. Then, the focus of the image is detected by a focus detection part 17 and the detected result is arithmetically processed by an arithmetic processing part 18. A lens control part 19 determines the rotational amount of the camera lens 15 or the projection lens 12 according to the arithmetic result, and allows a camera lens driving part 16 or a projection lens driving part 13 to rotate each lens to perform focusing. In the focusing, either the camera lens 15 or the projection lens 12 is fixed and the other is focused. When the peak of luminance change is not changed to attain a saturation state by alternately repeating the focusing of the respective lenses, the best focusing is obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projection display device that displays an image on a projection surface and an automatic focus adjustment method thereof, and in particular, a projection type that can automate setting adjustment when the distance between the projection surface and the projector device is variable. The present invention relates to a display device and an automatic focus adjustment method thereof.

  Conventionally, when an image is projected onto a screen using a projection display device (projector), it is first necessary to perform a focusing operation (focus adjustment) of the image projected on the projection surface of the screen. In the focus adjustment of the projector, when the distance between the projector main body and the projection surface is variable, it is necessary to manually adjust the focus according to the projection distance, which is troublesome for the user. In order to cope with such a variable projection distance, an autofocus system that automatically performs focus adjustment has been proposed.

  As an apparatus for performing focus adjustment by autofocus, for example, in Patent Document 1, an adjustment image pattern projected on a screen is photographed by a CCD camera or the like, and the photographed adjustment image pattern is input again from an input circuit. A focus adjustment device has been proposed that performs autofocus adjustment by comparing the frequency components of this input pattern and driving the projection lens with an electric motor until a predetermined high frequency component is configured.

In Patent Document 2, a test pattern projected from a projector is captured by a monitor camera, data of the captured monitor image is analyzed, and a focus detection unit determines a best focus point (a point on the sensor camera). A projector and automatic screen position adjustment method and apparatus for adjusting the focus of a projection lens according to the determined best point are disclosed.
JP 2000-28901 A JP 2000-241874 A

  The autofocus according to the conventional technique as described above is executed using a fixed focus lens of a sensor camera that captures a test pattern or the like, and is premised on the focus of the lens of the sensor camera when performing focus adjustment. For example, when the installation position of the projection display device and the screen is almost determined and the lens of the sensor camera can be focused, the above conventional technique can be applied. When the positions of the apparatus and the screen are variable, if there is a position where the lens of the sensor camera is out of focus, the focus lens accuracy of the projection lens is lowered.

  Therefore, in order not to lower the focus adjustment accuracy, a camera lens drive unit is provided in the sensor camera so that the focus adjustment of the camera lens of the sensor camera can be performed, and the lens of the sensor camera is in focus. By adjusting the focus of the projection lens, an optimum focus position of the projection lens can be obtained. However, a method for automatically obtaining the optimum focus position of both the camera lens and the projection lens of the sensor camera has not been proposed.

  The present invention has been made in view of the above circumstances, and by providing a lens driving unit that drives the camera lens and the projection lens of the sensor camera, the focus adjustment of both the camera lens and the projection lens is automatically performed. It is an object of the present invention to provide a projection type display device and an automatic focus adjustment method for the projection type display device which are performed in the above-described manner and increase the degree of freedom of projector installation.

  The first technical means includes a projection lens capable of performing focus adjustment, a sensor camera that captures an image projected by the projection lens, a focus detection unit that detects a focus of the image captured by the sensor camera, An arithmetic processing unit that calculates a detection result detected by the focus detection unit, a lens control unit that determines the amount of rotation of the projection lens according to the result calculated by the arithmetic processing unit, and the projection according to the determination of the lens control unit A projection lens driving unit that rotates the lens, and the projection camera automatically adjusts the focus of the projection lens by rotating the projection lens by the projection lens driving unit. A camera lens that can be adjusted, and a rotation of the camera lens to adjust the focus of the camera lens. The lens control unit can automatically adjust the focus of the camera lens by driving the camera lens driving unit according to the result calculated by the arithmetic processing unit. It is characterized by that.

  According to a second technical means, in the first technical means, the projection display device projects a pattern generation unit that generates a test pattern for performing focus adjustment, and a test pattern generated by the pattern generation unit. And the focus detection unit automatically adjusts the focus of the projection lens and the camera lens by detecting the focus of the test pattern imaged by the sensor camera. It is characterized by that.

  According to a third technical means, in the second technical means, the lens control unit drives the other lens with the focus position of one of the camera lens and the projection lens fixed. After performing the focus adjustment, the focus position of the lens for which the focus adjustment has been performed is fixed, the lens for which the focus adjustment has been performed first is released, and the lens is driven to perform the focus adjustment. The focus adjustment is performed automatically.

  According to a fourth technical means, in the third technical means, the lens control unit drives the other lens in a state where the focus position of one of the camera lens and the projection lens is fixed. Then, the operation of performing the focus adjustment is performed a plurality of times alternately for each lens.

  According to a fifth technical means, in the fourth technical means, the focus adjustment performed for each lens is performed until the peak value of the luminance change of each lens is saturated without being changed even when the focus adjustment is performed. It is characterized by repetition.

  A sixth technical means includes at least one camera lens having a sensor function in addition to the projection lens, and performs projection type display device automatic focus adjustment by detecting the focus of the projection image by the camera lens. In the automatic focus adjustment method of the display device, when performing the focus adjustment of one of the projection lens and the camera lens, the lens other than the lens for performing the focus adjustment is fixed, and the focus adjustment is performed. And a step of fixing the lens on which the focus adjustment has been performed and a step of adjusting the focus of another lens, and performing the focus adjustment of all the lenses of the projection display device It is.

  Seventh technical means performs focus adjustment by driving the other lens in the sixth technical means in a state where the focus position of one of the camera lens and the projection lens is fixed. The operation is performed a plurality of times for each lens.

  According to an eighth technical means, the focus adjustment performed after each lens in the seventh technical means is repeated until the peak value of the luminance change of each lens is saturated without being changed even when the focus adjustment is performed. It is characterized by that.

  According to the present invention, each of the camera lens and the projection lens of the sensor camera is provided with a lens driving unit, the test pattern projected on the screen is imaged by the sensor camera, and both the lens and the projection lens of the sensor camera are captured according to the imaging result. By adjusting the focus of the lens, the optimum focus position of both the lens of the sensor camera and the projection lens can be automatically obtained. Further, by repeating the above-mentioned camera lens and projection lens focus adjustment alternately, a more optimal focus position can be detected. As a result, the focus adjustment of both the camera lens and the projection lens can be automatically performed with high accuracy without depending on the distance between the projector and the screen, and the degree of freedom in installing the projection display device can be increased. .

  FIG. 1 is a diagram for explaining the configuration of an embodiment of a projection display apparatus according to the present invention. In FIG. 1, the projection display device 1 performs an adjustment start button 11 for inputting an instruction to start the focus adjustment, a projection lens 12 that can perform focus adjustment, and a focus adjustment of the projection lens 12. A projection lens drive unit 13 for driving the projection lens 12, a sensor camera 14 installed in front of the projection display device, a camera lens 15 of the sensor camera 14 capable of performing focus adjustment, and a camera lens 15 are driven. A camera lens driving unit 16 that adjusts the focus of the camera lens 15; a focus detection unit 17 that detects the focus of the image input by the sensor camera 14; an arithmetic processing unit 18 that calculates detection data of the focus detection unit 17; The projection lens 12 and the camera lens 1 according to the calculation data by the calculation processing unit 18. A lens control unit 19 that determines a rotation amount of the image, a pattern generation unit 20 that generates a test pattern, and a video output unit 21 for projecting the test pattern generated by the pattern generation unit 20. The image is projected onto the screen 2 by the light of the light source 22 included in the screen.

  In the focus adjustment of the projection display device, first, the projector is installed so that an image can be projected from the projection display device body onto the screen, the image is projected from the projection display device on the screen, and the focus adjustment of the projection display device is performed. Start. The focus adjustment is started when the operator presses an adjustment start button 11 provided on the main body of the projection display device 1. Further, focus adjustment may be started by remote operation from a remote controller (not shown).

FIG. 2 is a diagram illustrating an example of a test pattern for focus detection. When the adjustment start button 11 is pressed by the operator, the pattern generation unit 20 generates a test pattern 30 for focus detection, the video output unit 21 outputs an image of the test pattern 30, and the projection lens 12 displays the screen 2. A test pattern 30 is projected.
The focus detection test pattern 30 shown in FIG. 2 is formed by a white cross patch with a black background. Such a test pattern 30 is not limited to the form shown in FIG. 2, but it is desirable that the test pattern 30 has a form in which a change in luminance is large in horizontal scanning or vertical scanning of a projected image.

  After the test pattern 30 is projected, focus adjustment of the camera lens 15 and the projection lens 12 is started. First, the focus adjustment of either the camera lens 15 or the projection lens 12 is performed. At this time, while the focus of one of the camera lens 15 and the projection lens 12 is adjusted, the other lens is fixed. For example, when the focus adjustment of the camera lens 15 is performed first, the focus adjustment of the camera lens is performed with the focus position of the projection lens 12 fixed.

  The lens to be operated first may be either the camera lens 15 or the projection lens 12, but here the camera lens 15 is first operated. The test pattern 30 projected from the projection display device 1 forms an image on the screen 2 to generate a projected image. Then, the sensor camera 14 receives the reflected light on the screen and images the projection screen.

  The projection image of the test pattern 30 captured by the sensor camera 14 is input to the focus detection unit 17. The focus detection unit 17 analyzes the captured image data of the test pattern 30 and detects the location where the amplitude value of the horizontal signal or the vertical signal is high, or the presence or absence of a high-order frequency component by Fourier series expansion. The focus detection result in the focus detection unit 17 is processed by the calculation processing unit 18.

Then, the lens control unit 19 determines the rotation amount of the camera lens 15 according to the calculation data from the calculation processing unit 18 and outputs a command signal based on the determination to the camera lens driving unit 16. The camera lens driving unit 16 is configured by an electric motor or the like, and rotates the camera lens 15 according to a command signal from the lens control unit 19. Further, focus detection is performed by the focus detection unit 17.
Thus, the above process is repeated so that the best focus point of the camera lens 15 is set.
FIG. 3 is a diagram illustrating the relationship between the lens position and the luminance change. The position of the lens position where the luminance value is the peak shown in FIG. 3 is the best focus of the camera lens.
If the best focus point of the camera lens 15 can be detected, the focus adjustment of the camera lens 15 is terminated and the camera lens 15 is fixed.

  Then, the focus of the projection lens 12 is adjusted. The focus adjustment of the projection lens 12 is also executed by the same operation as the focus adjustment of the camera lens 15 as described above. That is, the projection image of the test pattern 30 captured by the sensor camera 14 is input to the focus detection unit 17. The focus detection unit 17 analyzes the captured image data of the test pattern 30 and detects the location where the amplitude value of the horizontal signal or the vertical signal is high, or the presence or absence of a high-order frequency component by Fourier series expansion. The detection result in the focus detection unit 17 is calculated by the calculation processing unit 18.

  Then, the lens control unit 19 determines the rotation amount of the projection lens 12 according to the calculation data from the calculation processing unit 18 and outputs a command signal based on the determination to the projection lens driving unit 13. The projection lens driving unit 13 is configured by an electric motor or the like, and rotates the projection lens 12 according to a command signal from the lens control unit 19. Further, focus detection by the focus detection unit 17 is performed. Thus, the above processing is repeated so that the best focus point of the projection lens 12 is set. The best focus point in the projection lens 12 can be detected from the position where the luminance peaks as shown in FIG.

  After the best focus point of the projection lens 12 is detected by the operation as described above, the projection lens 12 is fixed again, and the focus adjustment of the camera lens 15 is performed again by the same processing. For example, in the initial state, if the focus of the projection lens 12 is not in focus when the focus adjustment of the camera lens 15 is performed for the first time, the peak value of the peak value with respect to the lens position is low in the focus adjustment of the camera lens 15, and the luminance Therefore, the focus adjustment accuracy may be lowered. Therefore, by adjusting the focus of the camera lens 15 again after the best focus point of the projection lens 12 is detected, an adjustment with higher accuracy than the first adjustment can be performed. After the best focus point of the camera lens 15 is detected, the focus adjustment of the projection lens 12 is performed again.

  By repeating the operation as described above, the accuracy of focus adjustment of the camera lens 15 and the projection lens 12 becomes better than that before the adjustment. Then, this operation is repeated, and the position where there is no difference in peak value compared to the previous focus adjustment is the optimum focus position for both lenses. That is, it is possible to obtain an optimum focus position by repeating until the peak value of the luminance change of each lens is saturated without changing even if focus adjustment is performed.

FIG. 4 is a flowchart for explaining an example of the focus adjustment operation in the projection display device of the present invention. The focus adjustment operation in the projection display apparatus will be described according to the flow of FIG. 4 with reference to FIGS.
First, when focus adjustment is started, the pattern generation unit 20 generates a test pattern 30 (step S1), the video output unit 21 outputs the test pattern 30, and the projection lens 12 applies the test pattern 30 to the screen 2. Projection is performed (step S2).

  Then, the focus adjustment of the camera lens 15 is performed (step S3), and then the focus adjustment of the projection lens 12 is performed (step S4). Then, the focus adjustment of the camera lens 15 in step S3 and the focus adjustment of the projection lens 12 in step S4 are alternately repeated, and when the difference between the detection values before and after the focus adjustment almost disappears, that is, the luminance change of each lens. The focus adjustment is terminated when the peak value is saturated without changing even if the focus adjustment is performed. As described above, the focus adjustment performed first may be performed by the projection lens 12 instead of the camera lens 15.

  FIG. 5 is a flowchart for more specifically explaining the focus adjustment operation of the camera lens 15 in step S3 in FIG. First, when the focus adjustment of the camera lens 15 in step S3 is performed, the focus of the test pattern 30 projected on the screen 2 is imaged by the sensor camera 14 (step S31). Then, the captured test pattern 30 is detected by the focus detection unit 17 (step S32). Here, the captured image data of the test pattern 30 is analyzed to detect a part having a high peak value of the amplitude of the horizontal signal or the vertical signal, and the detection result is subjected to arithmetic processing by the arithmetic processing unit 18.

  Then, as a result of detecting a portion having a high peak value of the amplitude of the horizontal signal or vertical signal, it is determined whether or not a point where the peak value is a peak is detected (step S33), and if the peak is detected, the process is terminated. If not detected, the lens control unit 19 determines the rotation amount of the camera lens 15 according to the calculation data from the calculation processing unit 18 (step S34), and outputs a command signal based on the determination to the camera lens driving unit 16. The camera lens driving unit 16 drives the camera lens 15 in accordance with a command signal from the lens control unit 19 (step S35). When the camera lens focus adjustment is performed again, the process returns to step S31 and the same processing is performed.

  As described above, the focus adjustment of the camera lens 15 of the sensor camera 14 and the focus adjustment of the projection lens 12 are repeatedly performed alternately, and the position where the peak value with respect to the lens position reaches a peak is determined as the best focus of the camera lens. The focus adjustment ends. Accordingly, in step S33, when it is determined that the peak has been detected as a result of repeated focus detection, the focus adjustment is terminated.

  FIG. 6 is a flowchart for more specifically explaining the focus adjustment operation of the projection lens 12 in step S4 in FIG. First, when the focus adjustment of the projection lens 12 in step S4 is performed, the test pattern 30 projected on the screen 2 is imaged by the sensor camera 14 (step S41). Then, the focus of the captured test pattern 30 is detected by the focus detection unit 17 (step S42). Here, the captured image data of the test pattern 30 is analyzed to detect a part having a high peak value of the amplitude of the horizontal signal or the vertical signal, and the detection result is subjected to arithmetic processing by the arithmetic processing unit 18.

  Then, as a result of detecting a portion having a high peak value of the amplitude of the horizontal signal or vertical signal, it is determined whether or not a point at which the peak value is a peak is detected (step S43). If not detected, the lens control unit 19 determines the rotation amount of the projection lens 12 according to the calculation data from the calculation processing unit 18 (step S44), and outputs a command signal based on the determination to the projection lens driving unit 13. The projection lens driving unit 13 drives the projection lens 12 in accordance with a command signal from the lens control unit 19 (step S45). Then, when the focus adjustment of the projection lens 12 is performed again, the process returns to step S41 and the same processing is performed. Also in the case of the projection lens, in step S43, when it is determined that the peak is detected as a result of repeated focus detection, the focus adjustment of the projection lens 12 is terminated.

It is a figure for demonstrating the structure of one Example of the projection type display apparatus of this invention. It is a figure which shows an example of the test pattern for focus detection. It is a figure explaining the relationship between a lens position and a luminance change. It is a flowchart for demonstrating an example of the focus adjustment operation | movement in the projection type projector of this invention. 5 is a flowchart for more specifically explaining the operation of adjusting the focus of the camera lens in step S3 in FIG. 6 is a flowchart for more specifically explaining the focus adjustment operation of the projection lens in step S4 in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Projection type display apparatus (projector), 2 ... Screen, 11 ... Adjustment start button, 12 ... Projection lens, 13 ... Projection lens drive part, 14 ... Sensor camera, 15 ... Camera lens, 16 ... Camera lens drive part, 17 DESCRIPTION OF SYMBOLS ... Focus detection part, 18 ... Arithmetic processing part, 19 ... Lens control part, 20 ... Pattern generation part, 21 ... Image | video output part, 22 ... Light source, 30 ... Test pattern.

Claims (8)

  A projection lens that can perform focus adjustment, a sensor camera that captures an image projected by the projection lens, a focus detection unit that detects the focus of the image captured by the sensor camera, and a focus detection unit that is detected by the focus detection unit An arithmetic processing unit that calculates a detection result, a lens control unit that determines a rotation amount of the projection lens according to a result calculated by the arithmetic processing unit, and a projection lens that rotationally drives the projection lens according to the determination of the lens control unit A projection display device that automatically adjusts the focus of the projection lens by the rotation driving of the projection lens by the projection lens drive unit, and the sensor camera can perform focus adjustment. And a camera lens for rotating the camera lens to adjust the focus of the camera lens. A driving unit, and the lens control unit is configured to automatically adjust the focus of the camera lens by driving the camera lens driving unit according to a result calculated by the arithmetic processing unit. Projection type display device characterized by the above.   The projection display device according to claim 1, wherein the projection display device projects a pattern generation unit that generates a test pattern for performing focus adjustment, and a test pattern generated by the pattern generation unit. An image output unit for outputting an image, and the focus detection unit automatically adjusts the focus of the projection lens and the camera lens by detecting the focus of the test pattern imaged by the sensor camera. A projection type display device characterized.   3. The projection display device according to claim 2, wherein the lens control unit drives the other lens in a state where the focus position of one of the camera lens and the projection lens is fixed. After performing the focus adjustment, the focus position of the lens that has been subjected to the focus adjustment is fixed, the lens that was previously subjected to the focus adjustment is released, the focus is adjusted by driving the lens and performing the focus adjustment. A projection-type display device that performs adjustment automatically.   The projection display device according to claim 3, wherein the lens control unit drives the other lens in a state where the focus position of one of the camera lens and the projection lens is fixed. An operation for performing focus adjustment is performed a plurality of times alternately for each lens.   5. The projection display device according to claim 4, wherein the focus adjustment performed for each lens is repeated until a peak value of a luminance change of each lens is saturated without being changed even when the focus adjustment is performed. Projection type display device characterized by the above.   An automatic focus adjustment method for a projection display device that includes at least one camera lens having a sensor function in addition to the projection lens, and performs automatic focus adjustment of the projection display device by detecting the focus of the projection image by the camera lens. , The step of performing focus adjustment by fixing a lens other than the lens that performs the focus adjustment when performing focus adjustment of one of the projection lens and the camera lens, and the focus adjustment Fixing the lens that has been subjected to the adjustment, and adjusting the focus of the other lens, and performing the focus adjustment of all the lenses of the projection display device. Method.   7. The automatic focus adjustment method according to claim 6, wherein an operation of adjusting the focus by driving the other lens in a state where the focus position of one of the camera lens and the projection lens is fixed. An automatic focus adjustment method for a projection type display device, wherein the method is performed a plurality of times for each lens.   8. The automatic focus adjustment method for a projection display device according to claim 7, wherein the focus adjustment performed after each lens is saturated without changing the peak value of the luminance change of each lens even when the focus adjustment is performed. An automatic focus adjustment method for a projection display device, characterized by repeating until

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