JP2005338113A - Adjusting the projection size according to switching between multiple display modes with different resolutions - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily adjust a projection size in response to the switching of display modes. <P>SOLUTION: When instructions to switch the display mode are given, the projecting magnification of the projecting part in the switched display mode is adjusted based on a rate of change in two kinds of resolution corresponding to the display modes before and after switching. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for adjusting a projection size according to switching of a display mode in a projector capable of projecting and displaying an input image in a plurality of display modes having different resolutions.

  In recent years, projectors that project images onto screens are becoming popular. In this projector, the size of the projected image (hereinafter referred to as “projection size”) is changed by changing the magnification of the projection lens (projection magnification) so that the projected image is displayed at the maximum size on the screen. ) Has been adjusted. This projection size adjustment (hereinafter also simply referred to as “zoom adjustment”), for example, the resolution (number of pixels) and aspect of an image (hereinafter referred to as “input image”) represented by an image signal input from the outside. This is executed in accordance with a change in the type of image such as a ratio (a ratio between the length and width of the image) (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 8-292396

  By the way, in a conventional projector, a light valve such as a liquid crystal panel is used to output image light representing an image corresponding to an image signal given to the liquid crystal panel, and this image light is imaged on a screen to form an image. Is displayed. Usually, a plurality of types of images projected by the projector are assumed, and the resolution (number of pixels) of the image represented by the image signal given to the liquid crystal panel may differ from the resolution (number of pixels) of the liquid crystal panel. is there. In the conventional projector, when the resolution of the input image is different from the resolution of the liquid crystal panel, the image can be displayed in two types of display modes. The first display mode is a mode (hereinafter referred to as “through mode”) in which an image signal to be applied to the liquid crystal panel is generated without changing the resolution of the input image and the image is displayed (hereinafter referred to as “through mode”). The second display mode is a mode (hereinafter referred to as “normal mode”) in which an image signal to be applied to the liquid crystal panel is generated by enlarging or reducing the resolution of the input image, and the image is displayed. In these two types of display modes, the type of input image is the same, so the conventional projector has a problem described below with respect to the projection size of the image.

  FIG. 6 is an explanatory diagram showing the problems of the prior art. 6A shows an image substantially displayed on the liquid crystal panel in the normal mode and a projected image on the screen, and FIG. 6B shows the liquid crystal panel when the normal mode is switched to the through mode. The image substantially displayed and the projected image on the screen are shown. Here, it is assumed that the liquid crystal panel has a resolution of (1280 × 720) pixels with an aspect ratio of 16: 9. In addition, it is assumed that an image having an aspect ratio of 4: 3 and a resolution of (640 × 480) pixels is input to the projector as an input image. In addition, the aspect ratio of the screen is 16: 9 in accordance with the liquid crystal panel.

  Note that the liquid crystal panel used in the projector outputs image light representing an image as described above, and therefore does not strictly display an image. However, the image light output from the liquid crystal panel is imaged on the screen and displayed as an image. Therefore, in the following description, it is assumed that the liquid crystal panel used in the projector substantially displays an image.

  As shown in FIG. 6A, in the normal mode, the input image of (640 × 480) pixels has been enlarged 3/2 times so that it is displayed on the liquid crystal panel in the most enlarged state (960 × 720) It is converted into a pixel image. The image displayed on the liquid crystal panel is projected after being adjusted in zoom so as to be displayed at maximum on the screen. The projection magnification at this time is Ks.

  In the above state, when the display mode is switched from the normal mode to the through mode, an input image of (640 × 480) pixels is displayed as it is on the liquid crystal panel as shown in FIG. 6B. At this time, since there is no change in the type of image, zoom adjustment is not performed and the image is projected on the screen with the projection magnification Ks. As a result, in the through mode, there arises a problem that an image projected on the screen becomes smaller in accordance with a change in the resolution (number of pixels) of the image given to the liquid crystal panel.

  Note that FIG. 6 illustrates the case where the normal mode is switched to the through mode as an example, but the same problem occurs when the through mode is switched to the normal mode. However, there is a problem that when the image is adjusted so that the maximum image is displayed on the screen in the through mode, the projected image protrudes from the screen when the mode is changed to the normal mode.

  The present invention has been made to solve the above-described problems in the prior art, and in order to efficiently display an image projected by a projector on a screen, an input image is displayed in a plurality of types of display modes having different resolutions. An object of the present invention is to provide a technique capable of easily adjusting the projection size in accordance with switching of the display mode in a projector capable of performing projection display.

In order to achieve the above purpose, the projector according to the present invention provides:
A projector capable of projecting an input image represented by a supplied input image signal on a screen in a plurality of display modes having different resolutions,
An image display device for forming a display image to be projected on the screen;
An image processing unit that generates, from the input image, the display image including an image having a resolution corresponding to the indicated display mode;
A projection unit that projects the display image onto the screen;
A control unit for adjusting the projection magnification of the projection unit,
The controller is
When the switching of the display mode is instructed, the projection magnification of the projection unit in the display mode after the switching is adjusted based on the two types of resolution change rates corresponding to the display modes before and after the switching. To do.

  According to the projector of the present invention, the projection magnification in the display mode after switching can be adjusted according to the display mode switching instruction. Therefore, when the input image signal does not change, switching between a plurality of types of display modes having different resolutions occurs. Even in this case, the image size of the projected image can be easily adjusted.

  Further, the control unit is configured so that a size of an image projected on the screen in the display mode after switching is equal to a size of an image projected on the screen in the display mode before switching. It is preferable to determine the projection magnification of the projection unit in the display mode after switching based on the projection magnification of the projection unit and the rate of change in the resolution in the display mode before switching.

  In this way, even when the display mode is switched, the same image size can be projected and displayed without changing the size of the image projected on the screen.

  The present invention can be realized in various forms in addition to the configuration as the projector described above. For example, the invention can be realized in the form of a projector, an adjustment method thereof, a projection size adjustment device, an adjustment method, and the like. Is possible.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Overall configuration of the device:
B. Adjusting the projection size by switching the display mode:
B1. Adjustment procedure:
B2. Adjustment effect:
C. Variations:

A. Overall configuration of the device:
FIG. 1 is an explanatory diagram showing a projection display system using the projector of the present invention. The projector 100 of the present invention projects an image (input image) represented by an image signal (input image signal) input from an image supply device (not shown) such as a computer, a video tape recorder, a DVD player, etc., onto the screen SC. . Further, the user can control various operations of the projector using a remote controller (hereinafter referred to as “remote input device”) 102 and an operation panel (hereinafter referred to as “key input device”). The screen SC has a length of 9L in the vertical direction and a length of 16L (L: unit length) in the horizontal direction. That is, the screen SC is a so-called wide screen having an aspect ratio of 16: 9.

  FIG. 2 is a block diagram illustrating the overall configuration of the projector 100. The projector 100 includes a key input device 101 and a remote control input device 102 for inputting user instructions and the like, an image signal processing unit 140 for processing an input image signal input via the image input connector 103, An image display unit 150 for projecting and displaying an image, a projection zoom lens 120, a zoom control unit 130, and a control unit 110 for controlling the above-described functional units are provided.

  The control unit 110 is a microcomputer having a CPU and a memory (not shown), and functions as a display control unit 112, a parameter storage unit 114, and a zoom adjustment unit 116 by executing a program stored in the memory. Note that these functions may be constructed by hardware.

  In the projector 100, an image signal input via the image input connector 103 is input to the image signal processing unit 140.

  The image signal processing unit 140 implements various functions such as a function of detecting the type of image such as the resolution and aspect ratio of the input image signal, an analog-digital conversion function, and an image processing function. That is, the image signal processing unit 140 detects the type of image and supplies information indicating the detected type of image to the control unit 110. At this time, the supplied information is stored in the parameter storage unit 114 of the control unit 110. Further, the display control unit 112 of the control unit 110 determines a control condition for each functional block based on the supplied information indicating the type of image, and sets a parameter indicating the determined control condition for each functional block. Set the value. In addition, a parameter value indicating the determined control condition is also stored in the parameter storage unit 114. For example, the image signal processing unit 140 is set with various parameter values such as input image processing conditions, such as image size and operating frequency, according to the type of image.

  Then, when the input image signal is an analog signal, the image signal processing unit 140 converts the analog signal into a digital signal based on an instruction from the display control unit 112 and temporarily writes it in a memory (not shown). The digital data stored in the memory is read and output to the image display unit 150. Various image processing such as image size conversion (enlargement or reduction, image distortion correction, etc.) or conversion into a format that can be processed by the image display unit 150 is executed in the process of writing to and reading from the memory. Thus, a display image signal is generated. When the input image signal is a digital signal, the process of converting the analog signal into a digital signal is omitted.

  The image display unit 150 includes an optical system including a liquid crystal panel 152, an illumination device, an optical lens, and the like, and outputs a display image signal input from the image signal processing unit 140 as image light. The image light output from the image display unit 150 is projected onto the screen SC via the projection zoom lens 120.

  The projection size of the image projected on the screen SC changes when the zoom control unit 130 changes the zoom position of the projection zoom lens 120 in accordance with an instruction from the zoom adjustment unit 116 of the control unit 110. The adjustment of the zoom position is executed according to an instruction given from the zoom adjustment unit 116 to the zoom control unit 130 according to the adjustment amount input by the user using the key input device 101 or the remote control input device 102. Alternatively, the projection size on the screen SC may be detected and the zoom position may be automatically adjusted. For automatic zoom position adjustment, various general methods such as the method described in Patent Document 1 described in the related art can be used, and thus the description thereof is omitted here.

  By the way, the user can switch the display mode to either “through mode” or “normal mode” during the display of the projected image using the key input device 101 or the input device 102 to display the projected image. The “through mode” is a first display mode that displays an image using the input image at the same resolution, and the “normal mode” is an image with the highest resolution within the resolution of the liquid crystal panel. This is a second display mode in which an image is displayed by enlarging or reducing the resolution of the input image.

  When the display mode is switched as described above, the projection size is adjusted by changing the projection magnification of the projection zoom lens 120 as described below.

  The image signal processing unit corresponds to the image processing unit of the present invention, and the image display unit 150 or the liquid crystal panel 152 corresponds to the image display device of the present invention. The projection zoom lens 120 and the zoom control unit 130 correspond to the projection unit of the present invention.

B, Projection size adjustment by switching display mode:
B1. Adjustment procedure:
FIG. 3 is a flowchart showing zoom adjustment processing executed when the display mode is switched. When the display mode is switched from the normal mode to the through mode or from the through mode to the normal mode during the projection display, the zoom adjustment unit 116 performs zoom adjustment shown in FIG. Processing is executed.

  First, the currently set projection magnification (hereinafter referred to as “set projection magnification”) Ks is acquired (step S100). The set projection magnification is stored in the parameter storage unit 114 after the zoom adjustment or automatic zoom adjustment performed by the user as described above, or is stored in the parameter storage unit 114 in the process in step S130 described later. Therefore, it can be acquired by reading it.

  Here, FIG. 4 is an explanatory diagram showing an example of the projection magnification characteristic indicating the relationship between the zoom position and the projection magnification in the projection zoom lens 120. The projection magnification can be easily obtained from the zoom position of the projection zoom lens 120 by utilizing the projection magnification characteristic. Specifically, information indicating the projection magnification characteristic of FIG. 4 is stored in the parameter storage unit 114. The zoom adjustment unit 116 acquires the zoom position (set zoom position) Ps of the projection zoom lens 120 via the zoom control unit 130 when zoom adjustment is executed. Then, referring to the projection magnification characteristic information stored in the parameter storage unit 114, as shown in FIG. 4, the corresponding set projection magnification Ks can be easily obtained. The projection magnification characteristic is an example and is not limited to this. An appropriate projection magnification characteristic may be used according to the projection zoom lens to be configured.

  Also, a rate of change ΔK of the resolution of the image applied to the liquid crystal panel that is generated when the display mode is switched is acquired (step S110). This change rate ΔK is the resolution (number of pixels) after switching the display mode with respect to the resolution (number of pixels) before switching the display mode of the image signal generated based on the input image signal to generate an image signal to be given to the liquid crystal panel. ) Ratio may be calculated. Each resolution is a control condition necessary for controlling the operation of the image signal processing unit 140, and is stored in the parameter storage unit 114 in accordance with the switching of the display mode. Accordingly, the zoom adjustment unit 116 can read the resolution of the image before and after the display mode switching stored in the parameter storage unit 114 and obtain the change rate ΔK.

Next, the projection magnification (adjustment projection magnification) Kadj to be set after switching the display mode is calculated from the acquired current setting projection magnification Ks and change rate ΔK according to the following equation (1) (step S120).
Kadj = Ks / ΔK (1)

  Then, a zoom position (adjusted zoom position) Padj corresponding to the obtained adjustment projection magnification Kadj is determined (step S130). The adjustment zoom position Padj can be easily obtained as shown in FIG. 4 with reference to the information indicating the projection magnification characteristic stored in the parameter storage unit 114.

  Information on the determined adjustment zoom position Padj is input to the zoom control unit 130. The zoom control unit 130 performs control so that the zoom position of the projection zoom lens 120 becomes the adjustment zoom position Padj. Then, the contents of the set projection magnification Ks and the set zoom position Ps stored in the parameter storage unit 114 may be rewritten to information on the adjustment projection magnification Kadj and the adjustment zoom position Padj.

  As described above, zoom adjustment processing is executed when the display mode is switched.

B2. Adjustment effect:
FIG. 5 is an explanatory diagram illustrating an example of an image projected on the screen when the normal mode display is switched to the through mode display. 5A shows an image substantially displayed on the liquid crystal panel 152 of the image display unit 150 and a projected image on the screen SC in the normal mode, and FIG. 5B shows the normal mode to the through mode. The image that is substantially displayed on the liquid crystal panel 152 and the projected image on the screen SC in the case of switching to is shown. Here, it is assumed that the liquid crystal panel 152 constituting the image display unit 150 of the projector 100 has an aspect ratio of 16: 9 and a resolution of (1280 × 720) pixels. Further, it is assumed that an image having an aspect ratio of 4: 3 and a resolution of (640 × 480) pixels is input to the projector 100 as an input image. The aspect ratio of the screen SC is 16: 9 in accordance with the liquid crystal panel 152.

  As shown in FIG. 5A, in the normal mode, the input image of (640 × 480) pixels is enlarged 3/2 times so as to be displayed on the liquid crystal panel 152 in the most enlarged state (960). × 720) Converted to a pixel image. Then, by adjusting the zoom position of the projection zoom lens 120, the image displayed on the liquid crystal panel is displayed at maximum on the screen SC. Note that the projection magnification at this time is Ks.

  On the other hand, when the display mode is switched from the normal mode to the through mode, an input image of (640 × 480) pixels is displayed as it is on the liquid crystal panel 152 as shown in FIG. At this time, the zoom adjustment process is executed, the zoom position of the projection zoom lens 120 is adjusted, and the projection magnification is set to the adjustment projection magnification Kadj (= Ks / ΔK). Thereby, even when the mode is switched to the through mode, the projected image is displayed on the screen SC at the maximum. That is, when switching from the normal mode to the through mode in the middle of display, the projection size can be adjusted to be the same as the projection size in the normal mode.

  In the example of FIG. 5, the case where the normal mode is switched to the through mode has been described as an example, but the same applies when the through mode is switched to the normal mode.

  As described above, in the projector 100 of this embodiment, when switching of the display mode is instructed, the zoom position of the projection zoom lens 120 is adjusted in accordance with this and projection of an image projected on the screen SC is performed. The size can be adjusted to be the same as the projection size before switching.

C. Variations:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

  In the above embodiment, the case where the aspect ratio of the liquid crystal panel 152 constituting the screen SC and the image display unit 150 is 16: 9 and the aspect ratio of the input image is 4: 3 is described as an example. It is not limited. The aspect ratio of each of the screen, the liquid crystal panel, and the input image may be any aspect ratio, and each combination is arbitrary.

  In the above embodiment, switching between the two display modes, the through mode and the normal mode, has been described. However, the present invention is not limited to this, and is applied to switching between a plurality of types of display modes having different preset resolutions. be able to.

  In addition, the image display unit of the above embodiment has been described by taking a configuration having a liquid crystal panel as an example. However, the present invention is not limited to this. Various image display units used when configuring a projector, such as an image display unit configured by using (), may be applied.

It is explanatory drawing which shows the projection display system using the projector of this invention. 1 is a block diagram showing an overall configuration of a projector 100. FIG. It is a flowchart which shows the procedure of the zoom position adjustment at the time of display mode switching. It is explanatory drawing which shows an example of the relationship between the zoom position of a projection zoom lens, and projection magnification. It is explanatory drawing which shows the example of the image projected on a screen at the time of switching from normal mode display to through mode display. It is explanatory drawing which shows the problem of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Projector 101 ... Key input device 102 ... Remote control input device 103 ... Image input connector 110 ... Control part 112 ... Display control part 114 ... Parameter storage part 116 ... Zoom adjustment unit 120 ... Projection zoom lens 130 ... Zoom control unit 140 ... Image signal processing unit 150 ... Image display unit 152 ... LCD panel SC ... Screen

Claims (3)

A projector capable of projecting an input image represented by a supplied input image signal on a screen in a plurality of display modes having different resolutions,
An image display device for forming a display image to be projected on the screen;
An image processing unit that generates, from the input image, the display image including an image having a resolution corresponding to the indicated display mode;
A projection unit that projects the display image onto the screen;
A control unit for adjusting the projection magnification of the projection unit,
The controller is
When the switching of the display mode is instructed, the projection magnification of the projection unit in the display mode after the switching is adjusted based on the two types of resolution change rates corresponding to the display modes before and after the switching. Yes Projector. The projector according to claim 1, wherein
The control unit is configured so that a projection size of an image projected on the screen in the display mode after switching is equal to a projection size of an image projected on the screen in the display mode before switching. Determining the projection magnification of the projection unit in the display mode after switching based on the projection magnification of the projection unit and the change rate of the resolution in the display mode before switching;
projector. In a projector capable of projecting an input image represented by a supplied input image signal on a screen in a plurality of display modes having different resolutions, an adjustment method for adjusting a projection magnification of a projection unit that projects the image,
When the switching of the display mode is instructed, the projection magnification of the projection unit in the display mode after the switching is adjusted based on the two types of resolution change rates corresponding to the display modes before and after the switching. How to adjust.

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