JP2002196736A - Projection size adjustment of projector according to aspect ratio - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily adjust the projection size of images according to aspect ratios corresponding to the images in such a manner that the projected images are efficiently maximally displayed on a screen. SOLUTION: A user arbitrarily sets either of a first display mode using the first aspect ratio as a reference and a second display mode using the second aspect ratio of the value smaller than the value of the first aspect ratio as a reference. When the first display mode is set at the display mode of the reference, the numbers of horizontal pixels of a first effective image area for displaying the first image having the first aspect ratio and a second effective image region for displaying the second image of the second aspect ratio are set equal. When the second display mode is set at the display mode of the reference, the numbers of the vertical pixels of the first and second effective image regions are set equal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for adjusting a projection size according to an aspect ratio of an image in a projector for projecting an image.

[0002]

2. Description of the Related Art A projector for projecting an image can often display an image represented by an input image signal on a screen in an enlarged manner, and thus is often used for a presentation or the like. 2. Related Art A projector generally has a configuration in which an image formed by an image display device such as a liquid crystal panel is projected on a screen via a projection lens.

The types of images that can be projected by a projector include images supplied from a computer (hereinafter, referred to as “PCs”).
Also called "image." ), But also NTSC, PAL, S
Examples include a television image based on an ECAM format television signal and a high-vision image based on a high-vision signal.

As described above, there are various types of images that can be projected by the projector, and these images have different aspect ratios (ratio of vertical length to horizontal length). For example, the aspect ratio of a PC image or a television image is approximately 3: 4, and the aspect ratio of a high-definition image is approximately 9:16. Further, even in the case of a television image, as in the case of a television image supplied from a DVD player, a black image is embedded in the upper and lower ends in the vertical direction and the image has an effective aspect ratio of 9:16. There is also.

A projector is generally used to display a PC image from a conventional computer. The aspect ratio of an image display area of a liquid crystal panel used as an image display device is generally about 3: 2. It is often 4. For this reason, in a conventional projector, an image having an aspect ratio of 3: 4 is displayed in the entire image display area, and an image having an aspect ratio of 9:16 is located between black frames (black images) at the upper and lower ends of the image display area. It is displayed in the sandwiched area.

[0006]

FIG. 9 is an explanatory diagram showing a problem of the prior art. The screen SCR has a vertical length of 9 L, a horizontal length of 16 L (L: unit length), and an aspect ratio of 9:16. Here, as shown in FIG. 9A, the aspect ratio is 9:16.
Image [9:16] is projected on the screen SCR with a size substantially equal to the size of the screen. At this time, as shown by a broken line in FIG. 9B, an image PP [3: 4] having an aspect ratio of 3: 4 is displayed on a screen SC.
When the image is projected on R, the projected image PP [3: 4] may protrude vertically with respect to the screen SCR.

The projection of such a projected image can be adjusted by using a projection lens whose zoom ratio can be adjusted. However, such a projection lens is large and its cost is high. For this reason, a conventional projector uses a projection lens having a small zoom ratio. Therefore, in the conventional projector, there is a case where the projection size on the screen cannot be adjusted by the projection lens. For this reason, if you want to adjust the projection size and efficiently display the maximum image on the screen, move the position of the projector,
The distance from the screen had to be adjusted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and is intended to provide an image represented by an input image signal so that an image projected by a projector can be efficiently and maximally displayed on a screen. It is an object of the present invention to provide a technique capable of easily adjusting a projection size of an image according to a corresponding aspect ratio.

[0009]

In order to achieve the above object, a projector according to the present invention includes an image display device for forming an image corresponding to supplied image data, and an external image display device. An image signal processing unit that generates a display image signal that can be supplied to the image display device from an input image signal supplied from a supply device, a projection unit that projects an image formed by the image display device, and a first aspect The user can arbitrarily select one of a first display mode using a ratio as a reference and a second display mode using a second aspect ratio having a value smaller than the first aspect ratio as a reference. A reference mode setting unit that allows setting, wherein the image processing unit is represented by the input image signal by analyzing the input image signal. An aspect ratio determining unit for determining an aspect ratio of an image, and forming an image represented by the input image signal in the center of the image display area in the image display area of the image display device with the determined aspect ratio. When setting an effective image area to perform, when the effective image area is smaller than the image display area,
An image adjustment unit that sets a mask display area for forming a black image at an outer peripheral portion of the effective image area, and wherein the image adjustment unit switches the first display mode to a reference display mode. When set, the first
The number of horizontal pixels of a first effective image area for displaying a first image having an aspect ratio of and a second effective image area for displaying a second image having the second aspect ratio are as follows. When the second display mode is set to the reference display mode, the first and second display modes are set equal.
The number of vertical pixels in the effective image area is set to be equal.

[0010] When the display mode is set on the basis of the first aspect ratio, the projector of the present invention displays the second image having the second aspect ratio smaller than the value of the first aspect ratio. The second effective image area for displaying is set to be equal to the number of horizontal pixels of the first effective image area for displaying the first image having the first aspect ratio. Further, when the display mode is set based on the second aspect ratio, the first mode for displaying the first image having the first aspect ratio having a larger value than the second aspect ratio is set. The effective image area is
Is set equal to the number of vertical pixels in the second effective image area for displaying the second image having the aspect ratio of
Thus, it is possible to easily adjust an image having an aspect ratio different from the reference aspect ratio so that the image is efficiently and maximally displayed on the screen. Therefore, according to the aspect ratio corresponding to the image represented by the input image signal,
The projection size of the image can be easily adjusted. The aspect ratio indicates the ratio of the length in the vertical direction to the length in the horizontal direction of the rectangle.

Preferably, the first aspect ratio is 3: 4, and the second aspect ratio is 9:16.

With this arrangement, an image having an aspect ratio of approximately 3: 4, such as a PC image or a television image, and an image having an aspect ratio of approximately 9:16, such as a high-definition image, are converted into the detected aspect ratio. It is possible to efficiently display the maximum on the screen based on this.

[0013] The aspect ratio determining section determines a type of the input image signal based on a horizontal synchronizing signal and a vertical synchronizing signal corresponding to the input image signal and polarities of the horizontal synchronizing signal and the vertical synchronizing signal. Preferably, the corresponding aspect ratio is detected.

This makes it possible to easily detect the aspect ratio corresponding to the input image signal.

Further, when the input image signal is a television signal in one of NTSC, PAL, and SECAM formats, the aspect ratio determining unit may determine a part of the vertical synchronizing signal during one cycle period. It is preferable to detect the corresponding aspect ratio by checking the signal level of the image signal during the period.

A normal television signal in the NTSC, PAL, or SECAM format and a television signal supplied from a DVD player (hereinafter referred to as a “DVD signal”) correspond to a corresponding horizontal synchronization signal and vertical synchronization signal. The polarity specifications of the signal, the horizontal synchronization signal and the vertical synchronization signal are the same. However, while a typical television signal represents an image having an aspect ratio of 3: 4, a DVD signal has a black image embedded at the upper and lower ends of the television image, and the aspect ratio is effective. 9 shows a 9:16 image. In the above projector,
A period in which the signal level changes in the case of a general television signal (image signal whose aspect ratio is 3: 4) and does not change in the case of a DVD signal (image signal whose aspect ratio is effectively 9:16). , It is possible to determine whether the corresponding aspect ratio is 3: 4 or 9:16.

A method according to the present invention is an adjustment method for electronically adjusting a projection size of an image projected on a screen by a projector, comprising: a first display mode using a first aspect ratio as a reference; A step of arbitrarily setting one of a second display mode using a second aspect ratio having a value smaller than the first aspect ratio as a reference, and analyzing the input image signal. Determining an aspect ratio of an image represented by the input image signal; and, based on the aspect ratio, an image display area of an image display device provided in the projector, and Setting an effective image area for forming an image represented by the input image signal with the determined aspect ratio, and setting the effective image area Setting a mask display area for forming a black image at an outer peripheral portion of the image area when the image display area is smaller than the image display area; and setting the first display mode to a reference display mode. Sometimes, a first effective image area for displaying a first image having the first aspect ratio and a second effective image area for displaying a second image having the second aspect ratio Setting the number of horizontal pixels equal to each other; and setting the number of vertical pixels of the first and second effective image areas equal when the second display mode is set to the reference display mode. It is characterized by having.

According to the method of the present invention, similarly to the above projector, an image having an aspect ratio different from the reference aspect ratio can be easily adjusted so as to efficiently display the maximum on the screen efficiently. Therefore, the projection size of the image can be easily adjusted according to the aspect ratio corresponding to the image represented by the input image signal.

The present invention can be realized in various forms, for example, in the form of a projector, an adjustment method thereof, a projection size adjustment apparatus and an adjustment method, and the like.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described based on examples in the following order. A. Overall configuration of device: Aspect ratio detection: B1. Detection by signal format: B2. Detection by signal level determination: Projection size adjustment: C1.9: 16 image standard: C2.3: 4 image standard: Modification:

A. FIG. 1 is an explanatory diagram showing a projection display system using a projector of the present invention. The projector PJ of the present invention includes an image supply device (not shown), for example, a computer, a video tape recorder,
An image represented by an image signal supplied from a DVD player or the like is projected on the screen SCR. Also, the user
Various operations of the projector can be controlled using a remote controller (remote controller) RC attached to the projector PJ. The screen SCR has a size of 9 L in the vertical direction and 16 L (L: unit length) in the horizontal direction. That is, the screen SCR is a so-called wide screen having an aspect ratio (ratio of the length in the vertical direction to the length in the horizontal direction) of 9/16.

FIG. 2 is a block diagram showing the overall configuration of the projector PJ. The projector PJ includes image input terminals 20 and 22, an image signal conversion circuit 30, an aspect ratio adjustment circuit 40, a liquid crystal panel driving circuit 60, a liquid crystal panel 70, a lighting device 80, a projection optical system 90,
A controller 100, a mode detection circuit 110, and a remote control control circuit 120 are provided. Controller 11
Reference numeral 0 denotes a microcomputer having a CPU and a memory (not shown), which controls the operation of each of the blocks 30 to 90, 110, and 120 via the bus 100b. For example, the controller 100 operates as a mode detection control unit 102 and an aspect ratio control unit 104 by executing a program stored in a memory (not shown).

The analog image input terminal 20 has input terminals corresponding to a plurality of types of image signals. As an analog image signal, for example, an RGB signal output from a personal computer, a video tape recorder, a DV
A composite image signal or the like output from the D player is input.

The image signal conversion circuit 30 realizes various functions such as an analog-digital conversion function, a decoding function, a synchronization signal separation function, and an image processing function. That is,
The image signal conversion circuit 30 converts an analog image signal input from the image input terminal 20 into digital image data, synchronizes the converted digital image data with a synchronization signal, and stores a frame memory (not shown) in the image signal conversion circuit 30. Or read the digital image data written in the frame memory. Then, in the course of the writing and reading processes, various image processes are executed.

The image signal conversion circuit 30 can also process digital image data input from the digital image input terminal 22. In such a case, since a synchronization signal is supplied separately from the digital image signal, analog-digital conversion processing and separation processing are unnecessary.

The image signal conversion circuit 30 includes a selection circuit (not shown), and selects one of a plurality of image signals input from the image input terminals 20 and 22. The selection of the image signal is performed by the user instructing the selection of a desired image from the remote controller RC. Alternatively, it is possible to give an instruction by a panel switch (not shown) provided on the upper part of the projector.

The aspect ratio adjustment circuit 40 converts a display image signal capable of driving the liquid crystal panel 70 from an image represented by the image signal supplied from the image signal conversion circuit 30 in accordance with the aspect ratio of the image represented by the input image signal. Generate.

The mode detection control unit 102 detects the display mode of the image represented by the input image signal based on the data detected by the mode detection circuit 110.

The aspect ratio control unit 104 controls the operation of the aspect ratio control unit 40 based on the aspect ratio corresponding to the display mode detected by the mode detection control unit 102. The processing contents of the mode detection circuit 110 and the mode detection control unit 102, and the processing contents of the aspect ratio adjustment circuit 40 and the aspect ratio control unit 104 will be further described later.

The image signals input from the image input terminals 20 and 22 are input to a liquid crystal panel drive circuit 60 after various image processing is executed in an image signal conversion circuit 30 and an aspect ratio adjustment circuit 40. The liquid crystal panel drive circuit 60 generates a drive signal for driving the liquid crystal panel 70 according to the given display image signal. The liquid crystal panel 70 functions as a light valve (light modulator) that forms an image by modulating the illumination light emitted from the illumination device 80 according to a drive signal output from the liquid crystal panel drive circuit 60. The intensity of the illumination light of the illumination device 80 can be controlled by the controller 100.

The illumination light modulated in the liquid crystal panel 70 is emitted toward the screen SCR by the projection optical system 90 as light (image light) representing an image. Thus, an image is projected on the screen SCR. The projection magnification of the projection optical system 90 can be controlled by the controller 100.

The liquid crystal panel drive circuit 60 and the liquid crystal panel 70 correspond to the image display device of the present invention.
Further, the image signal conversion circuit 30, the aspect ratio adjustment circuit 40, the controller 100, and the mode detection circuit 110
Correspond to the image signal processing unit of the present invention. Further, the mode detection circuit 110 and the mode detection control unit 102 correspond to an aspect ratio determination unit of the present invention, and the aspect ratio adjustment circuit 40 and the aspect ratio control unit 104 correspond to an image adjustment unit of the present invention. In addition, the liquid crystal panel drive circuit 60 includes:
It is also possible to consider that it is included in the image signal processing unit instead of the image display device.

Although not shown, the liquid crystal panel 70 includes three liquid crystal panels corresponding to three colors of RGB. Therefore, each of the image signal conversion circuit 30, the aspect ratio adjustment circuit 40, and the liquid crystal panel drive circuit 60 has a function of processing image signals for three colors of RGB. The illuminating device 80 has a color light separation optical system that separates light from the light source into three colors of light. And a projection lens. As the configuration of the optical system of such a projector, various general configurations of the optical system of the projector can be used.

The user can use the remote control RC to
Various inputs can be made. The signal output from the remote controller RC is input to the controller 100 via the remote control circuit 120, and various processes are executed.

B. Aspect ratio detection: B1. Detection by Signal Format: FIG. 3 is an explanatory diagram showing a comparison of formats of synchronization signals for some inputtable image signals. As shown in the drawing, which display mode the input image signal corresponds to depends on the frequency of the horizontal synchronization signal HD and the vertical synchronization signal VD.
And the polarity of each signal can be uniquely detected.

The mode detection circuit 110 detects the polarities of the horizontal synchronization signal HD and the vertical synchronization signal VD, measures the respective frequencies, and supplies the results to the mode detection control unit 102. Mode detection control unit 10
2 has a table indicating a signal format corresponding to each display mode as shown in FIG. 3, and detects the corresponding display mode. For example, if the frequency of the horizontal synchronization signal HD is 56.476 kHz, the frequency of the vertical synchronization signal VD is 70.069 Hz, and their polarities are negative, the display mode XGA having a resolution of 1024 × 768 pixels.
70 is determined.

Various operating conditions of the projector are set according to the detected display mode. In particular, information on the aspect ratio of the image corresponding to the detected display mode is obtained from the table and supplied to the aspect ratio control unit 104.

B2. Detection by signal level judgment: NTS
A normal television (TV) signal in the format of C, PAL, or SECAM has an aspect ratio of 3: 4. Generally, DVD players can also output TV signals in these formats. However, an image represented by a television signal (hereinafter, referred to as a “DVD signal”) reproduced and supplied by a DVD player has a black image embedded in the upper and lower ends in the vertical direction, and an image to be actually displayed is displayed. Has an aspect ratio of 9:16. Therefore, for such a TV signal of the above format,
By simply analyzing the synchronization signal, the aspect ratio is 9: 1.
6 cannot be determined. Therefore, when the mode detection circuit 110 detects that the signal is a TV signal of NTSC, PAL, or SECAM format in the detection by the signal format, the mode detection circuit 110 further performs the following detection.

FIG. 4 shows a 1 V period of one cycle of the vertical synchronizing signal.
5 is an explanatory diagram showing a comparison between an image signal YS [3: 4] representing an image having an aspect ratio of 3: 4 and an image signal YS [9:16] representing an image having an aspect ratio of 9:16.

As can be seen by comparing the image signal YS [3: 4] of FIG. 4C with the image signal YS [9:16] of FIG. 4D, the vertical synchronizing signal of FIG. Period 1 of one cycle
In V, in a certain period at the front end and a part of a certain period at the rear end, the image signal YS [9:16] is a black image without any signal change, but the image signal YS [3:
4] has a period in which a signal change occurs. Therefore, at least a part of the period is set as the first detection period T1. In the present embodiment, a part of the rear end is the first detection period T1.
Is set to In both image signals, a part near the center where the signal change occurs is set as the second detection period T2. Note that these periods T1 and T2 can be defined by the count number of the horizontal synchronization signal HD in FIG. 4B from the synchronization start timing t1 of the vertical synchronization signal VD. In the two detection periods T1 and T2, the threshold V
T, for example, whether or not there is an image signal exceeding a signal level of 10%. When the signal level is higher than the threshold value VT, the H level is detected, and when the signal level is lower, the L level is detected.
Level is detected. The detection result is the mode detection control unit 1
02.

FIG. 5 is an explanatory diagram showing the relationship between the detection results and the aspect ratio determined in the two detection periods T1 and T2. When the detection result in the first detection period T1 is at the H level, there is an image signal exceeding the threshold value VT, and therefore the mode detection control unit 102 sets the aspect ratio regardless of the detection result in the second detection period T2. It is determined that the signal is a normal 4: 3 TV signal. When the detection result in the first detection period T1 is at L level and the detection result in the second detection period T2 is at H level, the aspect ratio is effectively T / 16 of 9/16.
It is determined that the signal is a V signal (DVD signal). Further, when the detection results in both of the two detection period periods T1 and T2 are at the L level, the determination cannot be made, so that the ratio determination (impossible to determine) is made, and the determination is performed again in the next period period of the vertical synchronization signal.

As described above, the aspect ratio of 3: 4
It can be detected whether the signal is a normal TV signal representing an image or a DVD signal representing an image whose aspect ratio is effectively 9:16. Information on the detected aspect ratio is
It is supplied to the aspect ratio control unit 104.

C. Projection size adjustment: The adjustment of the projection size differs depending on whether the display of an image having an aspect ratio of 9:16 is a reference or the display of a 3: 4 image is a reference.
Hereinafter, each case will be described separately. It should be noted that the display mode of the image having the aspect ratio of 9:16 or the image of 3: 4 is determined by the user using the remote controller RC.
Can be selected by The selected information is supplied to the aspect ratio control unit 104, and the display mode based on the supplied aspect ratio is set as a reference. Therefore, the remote controller RC, the remote controller control circuit 120, and the aspect ratio controller 104 of the controller 100 correspond to the reference mode setting unit of the present invention. The selection of the reference by the user can also be executed by an operation panel (not shown) on the upper part of the projector.

C1.9: 16 Image Reference: FIG. 6 is an explanatory diagram showing the adjustment of the projection size of an image having an aspect ratio of 9:16 when an image having an aspect ratio of 9:16 is used as a reference.

FIG. 6A shows image data supplied to the image display area MDA of the liquid crystal panel 70 when the aspect ratio of the image represented by the input image signal is determined to be 9:16. ing. The aspect ratio of the image display area MDA is 3: 4. In this example, the number of horizontal pixels Px is 1024 and the number of vertical pixels Py is 768. In this case, the aspect ratio control unit 104
As shown in (A), an image area ZP for displaying an image in the image display area MDA of the liquid crystal panel 70 based on the value ka (= 9/16) of the aspect ratio of the image to be displayed, Mask display area B on the outer periphery of image area ZP
P is determined. Specifically, these areas ZP, BP
Is determined as shown below.

The detected aspect ratio (9/9) is compared with the aspect ratio (3/4) of the image display area MDA.
When 16) is smaller, the number of horizontal pixels Pzx of the image area ZP is set equal to the number of horizontal pixels Px of the image display area MDA. Also, the number of vertical pixels Pzy of the image area ZP
Is set to a value (ka · Px) obtained by multiplying the number of horizontal pixels Px of the image display area MDA by the value ka of the aspect ratio. FIG.
In the example of (A), the number of horizontal pixels Pzx of the image area ZP is 10
The number of vertical pixels Pzy is set to 576 pixels in 24 pixels.

The number of vertical pixels Pby (= (P) from the upper end and the lower end of the image display area MDA of the mask display area BP.
y-Pzy) / 2) is set. Here, the upper and lower widths of the mask display area BP are set equally.
In this example, the number of vertical pixels P of the mask display area BP
by is set to 96 pixels.

The number of pixels in the horizontal and vertical directions of the image area ZP and the mask display area BP thus determined are set in the aspect ratio adjustment circuit 40. The aspect ratio adjustment circuit 40 outputs black image data to each pixel of the image display area MDA corresponding to the mask display area BP. Further, an image display area MDA corresponding to the image area ZP
For each pixel, the image data supplied from the image signal conversion circuit 30 is reduced or enlarged and output.

The image data can be reduced by a simple sampling process in which one pixel in a plurality of pixels represents one corresponding pixel in the reduced image, a process in which a smoothing process and a simple sampling process are combined, or a process in which a plurality of pixels are reduced. Can be easily realized by various kinds of reduction processing such as averaging processing in which the average value of the density of the image is set as the density value of the corresponding one pixel of the reduced image. Further, enlargement of an image can be easily realized by various interpolation processes such as linear interpolation and overweight average interpolation.

As described above, the image displayed in the set image area is displayed on the screen SCR as an image PP [9:16] having an aspect ratio of 9:16 as shown in FIG. Is projected. In the following, the distance between the screen SCR and the projector PJ and the zoom ratio of the projection lens are determined based on the projection size of the image PP [9:16] shown in FIG.
It is assumed that the size is set to be substantially equal to the size of the screen SCR as shown in FIG.

FIG. 7 is an explanatory diagram showing the adjustment of the projection size of an image having an aspect ratio of 3: 4 on the basis of an image having an aspect ratio of 9:16.

FIG. 7A shows an image PP [3: 4] projected on the screen SCR and having an aspect ratio of 3: 4.
Is shown. Image display area MDA of liquid crystal panel 70
As described above, the horizontal pixel number Px is 1024 pixels, the vertical pixel number Py is 768 pixels, and the aspect ratio is 3: 4.
Therefore, the image PP having the aspect ratio of 3: 4 [3:
4] can be displayed in the entire image display area MDA. However, the image area ZP described with reference to FIG.
If [9:16] is set to be projected with a size substantially equal to the screen SCR, the screen SC
The image PP [3: 4] projected on R protrudes vertically from the screen SCR as shown by the broken line in FIG. 7A.

Therefore, when it is determined that the aspect ratio is 3: 4, as shown in FIG. 7B, the aspect ratio control unit 104 sets the two aspect ratio values kb (=
3/4) and ka (= 9/16), an image area ZP for displaying an image in the image display area MDA of the liquid crystal panel 70, and a mask display area BP on the outer periphery of the image area ZP. To determine. Specifically, these areas ZP and BP are determined as described below.

The number of vertical pixels Pzy of the image area ZP is the same as that of the image having the aspect ratio of 9:16, that is, the value ka (= 9/16) of the aspect ratio is set to the image display area MD.
The value (ka · Px) multiplied by the number of horizontal pixels Px of A is set. The horizontal pixel number Pzx of the image area ZP is set to a value (Px · ka / kb) obtained by dividing the set vertical pixel number Pzy by the aspect ratio value kb (= ３). In this example,
The number of horizontal pixels Pzx of the image area ZP is set to 768 pixels, and the number of vertical pixels Pzy is set to 576 pixels.

The number of vertical pixels Pby from the upper end and the lower end of the image display area MDA of the mask display area BP is (Py
−ka · Px) / 2. Further, the number of horizontal pixels Pbx from the left end and the right end of the image display area MDA of the mask display area BP is set to (Py-Pzy) / 2. Here, the top and bottom and left and right widths of the mask display area BP are set equally. In the example of FIG. 7B,
The number of horizontal pixels Pbx of the mask display area BP is set to 128 pixels, and the number of vertical pixels Pby is set to 96 pixels.

The number of pixels in the horizontal and vertical directions of the image area ZP and the mask display area BP thus determined are set in the aspect ratio adjustment circuit 40. The aspect ratio adjustment circuit 40 outputs black image data to each pixel of the image display area MDA corresponding to the mask display area BP. Further, an image display area MDA corresponding to the image area ZP
For each pixel, the image data supplied from the image signal conversion circuit 30 is reduced or enlarged and output.

Note that the actual aspect ratio of the image represented by the input image signal may not be 3: 4 or 9:16 described above but may be slightly different. At this time, even if the image data supplied from the image signal conversion circuit 30 is reduced or enlarged and output for each pixel in the image area ZP, there may be a case where the pixel does not output the image data. In this case, black image data is output to pixels to which no image data is output.

As described above, as shown by the solid line in FIG. 7A, the image PP [3: 4] having the aspect ratio of 3: 4.
The maximum display can be efficiently performed so that the vertical direction of the image fits on the screen SCR.

As described above, in the projector PJ of this embodiment, an image having an aspect ratio of 9:16 is projected on a screen SCR having an aspect ratio of 9:16 at a size substantially equal to the screen SCR. When an image signal representing an image having an aspect ratio of 3: 4 is input when the setting is made, it is determined that the aspect ratio is 3: 4, and the image display on the liquid crystal panel 70 is accordingly displayed. In the area MDA, an image area ZP for forming an image represented by the input image data and a mask display area BP set on the outer periphery for forming a black image are set to be adjustable. As a result, the projected image is
It is possible to easily adjust the projection size so as not to protrude from the CR and efficiently display the projected image on the screen SCR at the maximum.

C2.3: 4 Image Reference: FIG. 8 is an explanatory diagram showing the image display area MDA of the liquid crystal panel 70 on the basis of an image having an aspect ratio of 3: 4.

When it is determined that the aspect ratio of the image represented by the input image signal is 3: 4, the image display area MDA has the horizontal pixel number Px of 1024 as described above.
Since the number of vertical pixels Py is 768 pixels and the aspect ratio is 3: 4, the image PP having the aspect ratio of 3: 4
It is possible to display the image [3: 4] in the entire image display area MDA. Therefore, the aspect ratio control unit 10
4 sets the size of the image area ZP equal to the image display area MDA, as shown in FIG. In this example,
The number of horizontal pixels Pzx is 1024 pixels and the number of vertical pixels Pzy is 76
It is set to 8 pixels.

If it is determined that the aspect ratio of the image represented by the input image signal is 9:16, the aspect ratio control unit 104 sets the image to be executed based on the image having the aspect ratio of 9:16. (Fig. 6
(A)), the number of horizontal pixels Pzx and the number of vertical pixels Pzy of the image area ZP are set.

D. Modifications: The present invention is not limited to the above-described examples and embodiments, and can be carried out in various modes without departing from the gist thereof. For example, the following modifications are also possible. is there.

In the above embodiment, the aspect ratio is 9:16.
In the above description, an example in which an image having an aspect ratio of 9:16 and an image having a 3/4 aspect ratio are displayed on the screen SCR is described, but the present invention is not limited to this.
This is applicable to the case where the maximum number of types of images are efficiently displayed on screens having various aspect ratios.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a projection display system using a projector of the present invention.

FIG. 2 is a block diagram illustrating an overall configuration of a projector PJ.

FIG. 3 is an explanatory diagram showing a comparison of formats of synchronization signals relating to some image signals that can be input;

FIG. 4 shows an image signal YS [3: 4] representing an image having an aspect ratio of 3: 4 and an image signal YS representing an image having an aspect ratio of 9:16 in a period 1V of one cycle of a vertical synchronization signal.
[9:16] is an explanatory diagram for comparison with FIG.

FIG. 5 is an explanatory diagram showing a relationship between detection results and an aspect ratio determined in two detection periods T1 and T2.

FIG. 6 is an explanatory diagram showing adjustment of a projection size of an image having an aspect ratio of 9:16 when an image having an aspect ratio of 9:16 is used as a reference.

FIG. 7 is an explanatory diagram showing the adjustment of the projection size of an image having an aspect ratio of 3: 4 based on an image having an aspect ratio of 9:16.

FIG. 8 is an explanatory diagram showing an image display area MDA of the liquid crystal panel 70 on the basis of an image having an aspect ratio of 3: 4.

FIG. 9 is an explanatory diagram showing a problem of the related art.

[Explanation of symbols]

 20, 22 image input terminal 30 image signal conversion circuit 40 aspect ratio adjustment circuit 60 liquid crystal panel drive circuit 70 liquid crystal panel 80 lighting device 90 projection optical system 100 controller 100b bus 102 mode detection control unit 104: Aspect ratio control unit 110: Mode detection circuit 120: Remote control circuit RC: Remote controller (remote controller) MDA: Image display area BP: Mask display area PJ: Projector

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) BA29 BA35 BB02 BB03 BB22 BC02 BC03 BC05 BD01 BD02 CA32 CB05 MM09

Claims (5)

[Claims] 1. A projector for projecting an image on a screen, comprising: an image display device for forming an image according to supplied image data; and an input image signal supplied from an external image supply device. An image signal processing unit that generates a display image signal that can be supplied to an image display device; a projection unit that projects an image formed by the image display device; a first display mode that uses a first aspect ratio as a reference A second value smaller than the first aspect ratio.
A second display mode using the aspect ratio as a reference, and a reference mode setting unit that allows the user to arbitrarily set one of the second display mode and the image processing unit, By analyzing, an aspect ratio determining unit that determines an aspect ratio of an image represented by the input image signal, of the image display area of the image display device, the input image signal in the center of the image display area. Along with setting an effective image area for forming an image represented by the determined aspect ratio, when the effective image area is smaller than the image display area, a black image is formed at an outer peripheral portion of the effective image area. An image adjustment unit for setting a mask display area for forming the image display unit, wherein the image adjustment unit is a display mode based on the first display mode. When it is set, a first effective image area for displaying the first image having the first aspect ratio, the second
The number of horizontal pixels in a second effective image area for displaying a second image having an aspect ratio of is set to be equal, and when the second display mode is set to a reference display mode, the first And the second effective image area is set to have the same number of vertical pixels. 2. The first aspect ratio is 3: 4 and the second aspect ratio is 9:16.
The projector as described. 3. The projector according to claim 1, wherein the aspect ratio determination unit determines a horizontal synchronization signal and a vertical synchronization signal corresponding to an input image signal and polarities of the horizontal synchronization signal and the vertical synchronization signal. A projector for detecting a corresponding aspect ratio by obtaining a type of the input image signal based on the input image signal. 4. The projector according to claim 3, wherein the aspect ratio determination unit is configured to determine whether the input image signal is a television signal in one of NTSC, PAL, and SECAM formats. A projector that detects a corresponding aspect ratio by checking a signal level of an image signal in a part of one period of a vertical synchronization signal. 5. An adjustment method for electronically adjusting a projection size of an image projected on a screen by a projector, the method comprising: a first display mode using a first aspect ratio as a reference; A second value smaller than the aspect ratio
A user arbitrarily setting one of a second display mode using the aspect ratio of the input image signal as a reference, and an aspect ratio of an image represented by the input image signal by analyzing the input image signal. Determining, based on the aspect ratio, the image represented by the input image signal in the center of the image display area, among the image display areas of the image display device provided in the projector, is determined. Set an effective image area for forming with an aspect ratio and, when the effective image area is smaller than the image display area, set a mask display area for forming a black image at an outer peripheral portion of the image area. And when the first display mode is set to the reference display mode, the first image having the first aspect ratio A first effective image area for displaying a second
Setting the same number of horizontal pixels in a second effective image area for displaying a second image having an aspect ratio of; and when the second display mode is set to a reference display mode, Setting the number of vertical pixels in the first and second effective image areas to be equal.