JP2014212467A - Projector and control method for projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector capable of urging readjustment of an installation position or the like by notifying a user of degradation in image quality due to distortion correction of a projected image.SOLUTION: In a projector 1 comprising image projection means 10, distortion correction means (trapezoidal distortion correction means 15), and correction amount setting means (control means 20), when a correction amount of distortion correction is not within a predetermined range (step S104:N), notification means (notification LED 25) makes notification (step S105).

Description

  The present invention relates to a projector and a projector control method.

  Conventionally, in a projector that projects an image on a projection surface such as a screen, the projection image is distorted when the installation position of the projector is not directly facing the projection surface (screen or the like) (projection distortion). For example, when tilt projection is performed with the projector tilted vertically or horizontally with respect to the screen, an image displayed on the screen is distorted in a trapezoidal shape (trapezoidal distortion). For this reason, a projector that corrects a projected image by forming an image that is distorted so as to cancel the trapezoidal distortion when an image is formed by a light modulation device is known, as in Patent Document 1.

  Further, as disclosed in Patent Document 2, a projector that automatically detects the installation angle of the projector and corrects the trapezoidal distortion is also disclosed.

JP-A-9-261568 JP 2003-283963 A

  However, in the trapezoidal distortion correction process disclosed in Patent Document 1, pixel thinning is performed on the image before correction, and thus there is a problem that the image quality of the image after correction deteriorates. If the correction amount is large, the pixel thinning amount increases and the deterioration of the image quality also increases. Therefore, in order to suppress the deterioration of the image quality, it is necessary to change the installation position of the projector and suppress the correction amount. In addition, in the trapezoidal distortion correction processing disclosed in Patent Document 2, since the trapezoidal distortion correction is performed by automatically detecting the installation angle of the projector, the user does not notice that the image is corrected and the image quality deteriorates. There was a problem of using the projector as it was.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A projector according to this application example includes an image projecting unit that modulates light emitted from a light source according to image information based on an image signal input from an image input terminal and projects the light onto a projection surface. A correction amount setting unit configured to set a correction amount for correcting a projection distortion of a projection image projected on the projection plane; and a distortion correction unit configured to perform distortion correction of the projection image based on the correction amount. And an informing means for informing that the distortion is corrected in the corrected image when the correction amount is not zero.

  According to this application example, when the correction amount of distortion correction is not zero, the notification unit notifies the user that distortion has been corrected in the projected image. As a result, it is possible to prevent the user from using the projector without noticing that the distortion has been corrected, and to urge the user to suppress the correction amount of the distortion correction, such as reviewing the installation position of the projector.

  Application Example 2 In the projector according to the application example described above, it is preferable that the notification unit performs notification by projecting a notification image on the projection surface in a menu setting mode in which setting items of the projector are set.

  According to this application example, the notification image is projected in the menu setting mode for setting the setting items of the projector. Thereby, when the menu setting mode is started when the use of the projector is started or when the setting is changed, it is possible to notify the user that distortion correction has been performed on the projected image.

  Application Example 3 In the projector according to the application example described above, the projector includes a plurality of the image input terminals, and the notification unit switches the projection surface when the image input terminal to which the image signal is input is switched. It is preferable to notify by projecting a notification image on top.

  According to this application example, the notification image is projected when the image input terminal to which the image signal is input is switched. Accordingly, when the image input terminal for inputting an image signal is switched at the start of use of the projector or when the input is changed, it is possible to notify the user that distortion correction has been performed on the projected image.

  Application Example 4 In the projector according to the application example described above, the projector further includes an image signal detection unit that detects whether an image signal is input to the image input terminal, and the notification unit is based on the image signal detection unit. When the detection state of the image signal changes, it is preferable to notify by projecting a notification image on the projection surface.

  According to this application example, the notification image is projected when the detection state of the image signal input to the image input terminal changes. Accordingly, when the detection state of the image signal is changed due to a change in connection of the video equipment input to the projector, it is possible to notify the user that distortion correction has been performed on the projected image.

  Application Example 5 In the projector according to the application example described above, it is preferable that the notification unit notifies when the correction amount exceeds a predetermined range.

  According to this application example, when the correction amount of the distortion correction applied to the projected image exceeds the predetermined range, the notification is not made if the correction amount is within the predetermined range, and exceeds the predetermined range. Notification can be made only in the case of. As a result, it is possible to notify the user only when the amount of distortion correction is large and it is better to review the installation position of the projector.

  Application Example 6 In the projector according to the application example described above, the projector further includes an input operation unit that receives an input operation, and the correction amount setting unit performs a predetermined correction from the input operation unit when the notification image is projected. It is preferable that the correction amount is changed to zero or within a predetermined range when an amount change operation is received.

  According to this application example, when the installation position of the projector cannot be changed, the distortion correction amount can be changed to zero or within a predetermined range, and deterioration of the image quality of the projected image can be suppressed. .

  Application Example 7 A projector control method according to this application example is a projector control method including an image projecting unit that modulates light emitted from a light source according to image information and projects the light onto a projection surface. A correction amount setting step for setting a correction amount for correcting the projection distortion of the projection image projected on the projection surface; a distortion correction step for executing distortion correction of the projection image based on the correction amount; and the correction amount is zero. If not, a notification step of notifying that the distortion correction has been performed on the corrected image is provided.

  According to this application example, when the correction amount of distortion correction is not zero, the notification step is executed to notify the user that distortion correction has been performed on the projected image. As a result, it is possible to prevent the user from using the projector without noticing that the distortion has been corrected, and to urge the user to suppress the correction amount of the distortion correction, such as reviewing the installation position of the projector.

1 is a block diagram showing a circuit configuration of a projector according to an embodiment. The front view which shows a liquid crystal light valve. Explanatory drawing which shows the principle of the installation angle detection of a projector. Explanatory drawing for demonstrating trapezoid distortion. Explanatory drawing for demonstrating trapezoid distortion correction. The figure which shows the state by which the alerting | reporting image was projected. The flowchart which shows operation | movement when a projector sets the correction amount. The flowchart which shows operation | movement of the menu setting mode of a projector. The flowchart which shows operation | movement when a projector switches the image input terminal and when the change of the detection state of an image signal is detected. 7 is a flowchart showing an operation when the projector receives a correction amount setting change operation during projection of a notification image.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the following embodiment does not limit the invention according to the scope of claims, and all combinations of features in the embodiment are based on the invention. It is not always essential to the solution.
In the present embodiment, trapezoidal distortion is described as an example of projection distortion. Trapezoidal distortion correction corresponds to distortion correction.

(Embodiment)
FIG. 1 is a block diagram illustrating a circuit configuration of the projector 1 according to the present embodiment.
As shown in FIG. 1, the projector 1 includes an image input terminal 6, an image projection unit 10, a trapezoidal distortion correction unit 15, an OSD processing unit 16, an image signal processing unit 17, an image signal input unit 18, an angle detection unit 19, and a control. It comprises means 20, storage means 21, light source control means 22, input operation means 23, notification LED 25, image signal detection means 26, power supply terminal 30, power supply section 31, etc., which are inside or outside the casing not shown. Is housed in.

  The image projection means 10 includes a light source 11, three liquid crystal light valves 12R, 12G, and 12B as light modulation devices, a projection lens 13 as a projection optical system, a liquid crystal drive means 14, and the like. The image projection means 10 modulates the light emitted from the light source 11 by the liquid crystal light valves 12R, 12G, and 12B, and projects the modulated image from the projection lens 13 to project the projected image on the projection surface such as the screen SC. indicate. The image projection unit 10 also corresponds to a notification unit.

The light source 11 includes a discharge-type light source lamp 11a made of an ultra-high pressure mercury lamp, a metal halide lamp, or the like, and a reflector 11b that reflects light emitted from the light source lamp 11a toward the liquid crystal light valves 12R, 12G, and 12B. ing.
Light emitted from the light source 11 is converted into light having a substantially uniform luminance distribution by an integrator optical system (not shown), and red (R), green (G), and blue, which are the three primary colors of light, by a color separation optical system (not shown). After being separated into each color light component of (B), it enters the liquid crystal light valves 12R, 12G, and 12B, respectively.

  FIG. 2 is a front view showing the liquid crystal light valves 12R, 12G, and 12B. The liquid crystal light valves 12R, 12G, and 12B are configured by a liquid crystal panel in which liquid crystal is sealed between a pair of transparent substrates. As shown in FIG. 2, on the inner surface of each transparent substrate, a transparent electrode (pixel electrode) capable of applying a driving voltage to the liquid crystal for each minute region (pixel 12p) is in a rectangular region (pixel region 12a). It is formed in a matrix.

When the liquid crystal driving unit 14 applies a driving voltage corresponding to the input image information to each pixel 12p, each pixel 12p is set to a light transmittance corresponding to the image information. Therefore, the light emitted from the light source 11 is modulated by passing through the liquid crystal light valves 12R, 12G, and 12B, and image light corresponding to image information is formed for each color light.
The formed image light of each color is synthesized for each pixel by a color synthesis optical system (not shown) to become color image light, and then enlarged and projected onto the screen SC or the like by the projection lens 13 to become a projection image.

  In the present embodiment, the projector 1 that projects using the light source lamp 11a as the light source is exemplified. However, the present invention is also applicable to a projector that projects using a light emitting diode (LED) light source or a laser light source as the light source. Can do.

  In the present embodiment, the image projection means 10 is exemplified by a transmissive liquid crystal type projection optical system using three liquid crystal light valves 12R, 12G, and 12B, but a reflective liquid crystal display method or a micromirror device method ( A light modulation device of another display method such as a light switch display method may be employed.

  Returning to FIG. 1, the control means 20 includes a CPU (Central Processing Unit) (not shown), a RAM (Random Access Memory) used for temporary storage of various data, and the like, and a control program stored in the storage means 21 ( The overall operation of the projector 1 is controlled by operating according to (not shown). That is, the control unit 20 functions as a computer together with the storage unit 21. The control unit 20 corresponds to a correction amount setting unit, and sets a correction amount for trapezoidal distortion correction in the trapezoidal distortion correction information 21 a of the storage unit 21.

  The storage means 21 is composed of a rewritable nonvolatile memory such as a flash memory or FeRAM (Ferroelectric RAM). The storage unit 21 stores a control program for controlling the operation of the projector 1, various setting data for defining operation conditions of the projector 1, and the like. In the present embodiment, the storage unit 21 stores trapezoidal distortion correction information 21a. The trapezoidal distortion correction information 21a stores a correction direction (vertical direction and horizontal direction) of the trapezoidal distortion correction, a correction amount, a correction amount corresponding to the installation angle detected by the angle detection unit 19, and the like. The trapezoidal distortion correction unit 15 performs trapezoidal distortion correction on the projected image based on the correction amount of the trapezoidal distortion correction information 21a.

  The input operation means 23 includes a plurality of operation keys for the user to give various instructions to the projector 1. The operation keys provided in the input operation means 23 include a power key for alternately switching on / off the power supply, an input switching key for switching a plurality of image input terminals 6 input to the image signal input means 18, and various types. There are a menu key for superimposing a setting menu for setting, a cursor key for the user to select a setting item from the menu, a determination key for determining various settings, an escape key for returning the screen being set, and the like.

  When the user operates various operation keys of the input operation unit 23, the input operation unit 23 outputs an operation signal corresponding to the operation content of the user to the control unit 20. The input operation means 23 may have a configuration including a remote controller (remote control) signal receiving means (not shown) and a remote controller (not shown) capable of remote operation. In this case, the remote controller emits an operation signal such as an infrared ray corresponding to the operation content of the user, and the remote control signal receiving means receives this and transmits it to the control means 20 as control information.

  The notification LED 25 is provided on the outer surface of the casing of the projector 1 (not shown) and notifies various operation states of the projector 1. In the present embodiment, the notification LED 25 corresponds to notification means and notifies that the correction amount of the trapezoidal distortion correction information 21a is outside a predetermined range.

  The angle detection unit 19 includes an acceleration sensor 19a (see FIG. 3) and the like, and detects the installation angle of the projector 1 based on an instruction from the control unit 20. Then, the detected installation angle is notified to the control means 20.

  Here, a method for detecting the installation angle of the projector 1 will be described. FIG. 3 is an explanatory diagram illustrating the principle of installation angle detection of the projector 1. This figure is a diagram showing the projector 1, its installation surface H, and the screen SC from the right side surface in the projection direction. The installation surface H is assumed to be horizontal. In the present embodiment, the acceleration sensor 19a is used to detect the installation angle of the projector 1. The acceleration sensor 19a is mounted inside the projector 1, and detects acceleration acting in the left direction (the rear of the projector 1) in the drawing on the one-dot chain line in FIG.

As shown in FIG. 3, when the projector 1 is installed at an installation angle θ, the acceleration component on the alternate long and short dash line is g · sin θ, as shown. The acceleration sensor 19a outputs a voltage corresponding to the acceleration component. Thereby, the angle detection means 19 can detect the installation angle of the projector 1 based on the voltage value output from the acceleration sensor 19a.
In the present embodiment, the acceleration sensor 19a is used. However, the mechanism is not limited to the acceleration sensor 19a as long as the installation angle of the projector 1 can be detected.

  Returning to FIG. 1, the light source control unit 22 controls the supply and stop of power to the light source 11 based on an instruction from the control unit 20, and switches on and off the light source 11.

  The image signal input means 18 receives image information from a plurality of image input terminals 6 from an external image output device such as a video reproduction device or a personal computer via a cable (not shown) or a communication device. The input image information is output to the image signal processing unit 17 and the image signal detection unit 26 based on an instruction from the control unit 20. Note that the image signal input unit 18 may include a receiving unit for wireless communication, optical communication, or the like, and input an image signal wirelessly from an external device.

  The image signal detection unit 26 outputs a detection result to the control unit 20 as to whether or not a valid image signal is input from the image input terminal 6 to the image signal input unit 18.

  The image signal processing unit 17 converts the image information input from the image signal input unit 18 into image information representing the gradation of each pixel of the liquid crystal light valves 12R, 12G, and 12B based on an instruction from the control unit 20. Here, the converted image information is classified into red (R), green (G), and blue (B) color lights, and a plurality of pixels corresponding to all the pixels of the liquid crystal light valves 12R, 12G, and 12B. Consists of values. The pixel value defines the light transmittance of the corresponding pixel, and the intensity (gradation) of light transmitted through each pixel and emitted is defined by this pixel value.

  The OSD processing unit 16 performs processing for superimposing and displaying an OSD (on-screen display) image such as a menu image or a message image on the projection image based on an instruction from the control unit 20. The OSD processing unit 16 includes an OSD memory (not shown), and stores OSD image information representing graphics, fonts, and the like for forming an OSD image.

When the control unit 20 instructs to superimpose the OSD image, the OSD processing unit 16 reads necessary OSD image information from the OSD memory, and outputs an image signal so that the OSD image is superimposed at a predetermined position on the projected image. The OSD image information is synthesized with the image information input from the processing means 17. The image information combined with the OSD image information is output to the trapezoidal distortion correction means 15.
If there is no instruction to superimpose the OSD image from the control unit 20, the OSD processing unit 16 outputs the image information input from the image signal processing unit 17 to the trapezoidal distortion correction unit 15 as it is.

  The trapezoidal distortion correction means 15 is input to suppress distortion (trapezoidal distortion) that causes the projected image to expand in the tilt direction when an image is projected with the projector 1 tilted with respect to the screen SC. Perform image data correction (keystone distortion correction). Based on the trapezoidal distortion correction instruction information input from the input operation unit 23 and the information on the installation angle of the projector 1 detected by the angle detection unit 19, the control unit 20 corrects the trapezoidal distortion correction to the trapezoidal distortion correction unit 15. The trapezoidal distortion correction means 15 performs trapezoidal distortion correction. The trapezoidal distortion correcting unit 15 corresponds to a distortion correcting unit.

The trapezoidal distortion correction is a process in which pixel values are thinned out from image data, and the projected image is reduced in the tilt direction. The trapezoidal distortion correction unit 15 outputs the corrected image data to the liquid crystal driving unit 14. To do.
Note that when the keystone distortion correction is not performed, the image data output from the OSD processing unit 16 is output to the liquid crystal driving unit 14 as it is.

  When the liquid crystal driving unit 14 drives the liquid crystal light valves 12R, 12G, and 12B according to the image information input from the OSD processing unit 16, that is, the pixel value for each pixel 12p, an image corresponding to the image information is projected from the projection lens 13. The projected image is displayed on the projection surface of the screen SC.

  The power supply unit 31 is supplied with electric power such as AC 100V from the outside via the power supply terminal 30. The power supply unit 31 converts input power (AC power) into predetermined DC power and supplies the power to each unit of the projector 1. In addition, the power supply unit 31 stops supplying power (operating power) necessary for image projection to each unit (power-on state) and operating power supply based on an instruction from the control unit 20. It is possible to switch between a state (standby state) of waiting for an operation for turning on.

Next, trapezoidal distortion correction by the trapezoidal distortion correcting unit 15 will be described with reference to FIGS. 4 and 5.
FIG. 4 is an explanatory diagram for explaining trapezoidal distortion, and shows a state in which keystone distortion correction is not performed on image data. 1A is a front view of the liquid crystal light valves 12R, 12G, and 12B as viewed from the light incident surface side, and FIG. 1B is a side view showing how the projector 1 projects horizontally. FIG. 4C is a front view showing a projected image displayed on the screen SC at that time. Further, FIG. 4D is a side view showing a state in which the projector 1 is projected in a tilted state, and FIG. 4E is a front view showing a projected image displayed on the screen SC at that time. .

  In FIG. 4, the left and right directions (horizontal left and right) toward the liquid crystal light valves 12R, 12G, and 12B are ± x directions, and the up and down directions (vertical up and down) are ± y directions, and left and right toward the screen SC. The direction (left and right in the horizontal direction) is the ± X direction, and the vertical direction (up and down in the vertical direction) is the ± Y direction. Here, the X direction and the Y direction of the screen SC correspond to the x direction and the y direction of the liquid crystal light valves 12R, 12G, and 12B, respectively. For example, the upper right (+ x, + y side) of the pixel region 12a. The light transmitted through the pixels is projected on the upper right (+ X, + Y side) of the screen SC.

  4 and 5, the lattice pattern shown in the pixel area 12a and the projected image Ga corresponds to the image formed in the pixel area 12a and the projected image Ga projected on the screen SC. These lines are supplementarily added for the purpose of illustration, and do not mean that such a pattern is actually displayed.

  As shown in FIG. 4A, when the keystone distortion correction is not performed, the liquid crystal light valves 12R, 12G, and 12B are images based on the image data input from the keystone distortion correction means 15 (input image Gi). Are formed in the entire pixel region 12a. That is, in this case, the area for forming the input image Gi (image forming area 12i) coincides with the pixel area 12a. Here, as shown in FIGS. 4B and 4C, when the projector 1 is installed horizontally and performs projection without tilting with respect to the screen SC, a projected image Ga ( The input image Gi) has the same rectangular shape as the pixel region 12a.

  On the other hand, as shown in FIGS. 4D and 4E, when the projector 1 is installed to be inclined with respect to the screen SC and projected upward (in the + Y direction), it is displayed on the screen SC. The projected image Ga is enlarged in the ± X direction and the + Y direction and distorted into a trapezoidal shape as it goes in the tilt direction (+ Y direction). In the present embodiment, trapezoidal distortion correction in the case where tilt projection in the + Y direction (vertical direction) is performed will be described.

  FIG. 5 is an explanatory diagram for explaining trapezoidal distortion correction. FIG. 5A is a front view of the liquid crystal light valves 12R, 12G, and 12B as viewed from the light incident surface side, and FIG. It is a front view which shows the projection image as a correction | amendment image displayed on screen SC when performing an inclination projection.

  The trapezoidal distortion correction unit 15 performs pixel value decimation from the image data input from the OSD processing unit 16 and reduces the projection image Ga as it goes in the tilt direction (+ Y direction), compared to the case where correction is not performed. Make appropriate corrections.

Specifically, as shown in FIG. 5 (a), the pixel region 12a of the liquid crystal light valves 12R, 12G, and 12B has a trapezoidal shape opposite to the projection image Ga that is not corrected, that is, the tilt direction (+ y direction). An image forming area 12i having a shape in which the lateral width is reduced toward the head is set. Further, the input image Gi is formed in the image forming area 12i by thinning out more pixel values from the image data at a position where the degree of enlargement by tilt projection is higher.
The trapezoidal distortion correcting unit 15 corrects the image data so that the light transmittance of each pixel 12p included in the region 12n outside the image forming region 12i is minimized.

  As a result, as shown in FIG. 5B, the distortion of the input image Gi due to the tilt projection is corrected, and the region Gn in the projection image Ga corresponding to the region 12n is hardly irradiated with light. The image Gi is displayed on the screen SC in a regular shape (rectangular shape). In order to compensate for the lack of gradation information associated with thinning out pixel values, it is desirable to correct the pixel values of the pixels adjacent to the thinning target pixel according to the thinned pixel values.

  Next, the operation of the projector 1 of the present embodiment will be described using the flowcharts of FIGS. 7 shows the operation when the projector 1 sets the correction amount of the keystone distortion correction, FIG. 8 shows the operation of the menu setting mode of the projector 1, and FIG. 9 shows the image input terminal to which the projector 1 is input to the image signal input means 18. FIG. 10 is a flowchart showing the operation when the change in the detection state of the image signal is detected, and the operation when the projector 1 accepts the correction amount setting change operation during the notification image projection. It is.

  FIG. 6 is a diagram showing a state in which the notification image PA1 is projected, FIG. 6A is a diagram showing the notification image PA1 in the menu setting mode, and FIG. It is a figure which shows alerting | reporting image PA1 in the state which switched the terminal 6, The figure (c) is a figure which shows alerting | reporting image PA1 in the state which detected the change of the image signal detection state. Note that the notification image PA1 illustrated in FIG. 6 is used as appropriate in the description of the flowcharts of FIGS.

[Correction amount setting]
As shown in FIG. 7, when the projector 1 starts a trapezoidal distortion correction amount setting operation (step S101), the control unit 20 sets a trapezoidal distortion correction amount in the trapezoidal distortion correction information 21a (step S102). ). Specifically, when the projector 1 is turned on, and when the angle detection unit 19 detects a change in the installation angle while the projector 1 is operating, the correction amount based on the installation angle detected by the angle detection unit 19 is trapezoidal. This is set in the distortion correction information 21a. When a correction amount change operation by the input operation means 23 is received, a correction amount based on the operation is set in the trapezoidal distortion correction information 21a. Next, the process proceeds to step S103. Step S102 corresponds to a correction amount setting step.

  In step S103, the control unit 20 instructs the trapezoidal distortion correction unit 15 to execute the trapezoidal distortion correction based on the correction amount set in the trapezoidal distortion correction information 21a. Next, the process proceeds to step S104. Step S103 corresponds to a distortion correction step.

  In step S104, the control means 20 checks whether or not the correction amount of the trapezoidal distortion correction is within a predetermined range. When the correction amount is within the predetermined range (step S104: Y), the process proceeds to step S106. If the correction amount is outside the predetermined range (step S104: N), the process proceeds to step S105. Here, the predetermined range represents, for example, whether the correction amount is in the range of +5 to −5, or whether the correction amount is 0, that is, whether trapezoidal distortion correction is not performed.

  In step S105, the control unit 20 informs the correction LED that the correction amount is outside the predetermined range by the notification LED 25, and the process proceeds to step S107. Step S105 corresponds to a notification step.

  In step S106, the control unit 20 terminates the notification if the notification LED 25 notifies that the correction amount is out of the predetermined range, and the process proceeds to step S107.

  In step S107, the operation flow ends.

[Operation in menu setting mode]
As shown in FIG. 8, when the menu setting mode is started by the menu key of the input operation unit 23 or the like while the projector 1 is operating (step S201), the control unit 20 causes the image projection unit 10 to execute the menu setting screen (FIG. 6). (See (a)) is projected (step S202), and the process proceeds to step S203.

  In step S203, the control means 20 checks whether or not the correction amount of the keystone distortion correction is within a predetermined range. If the correction amount is within the predetermined range (step S203: Y), the process proceeds to step S205. If the correction amount is outside the predetermined range (step S203: N), the process proceeds to step S204.

  In step S204, the control unit 20 causes the image projection unit 10 to project the notification image PA1 that notifies that the correction amount exceeds the predetermined range while being superimposed on the menu setting screen, and the process proceeds to step S205. The notification image PA1 is shown in the upper right of FIG. The notification image PA1 shows the direction and amount of correction of trapezoidal distortion.

  Note that the notification image PA1 illustrated in FIG. 6 indicates that the trapezoidal distortion correction direction is the vertical direction and the correction amount is +6, and that the correction is reduced in the horizontal direction as it goes upward. Although not shown, when the direction of trapezoidal distortion correction is the horizontal direction, the notification image PA1 is an image showing that the rotation is 90 degrees and that the correction is reduced in the vertical direction toward the right or left.

  In step S <b> 205, the control unit 20 checks whether or not an operation for ending the menu setting mode has been received by using the menu key of the input operation unit 23 or the like. When the end operation of the menu setting mode is received (step S205: Y), the process proceeds to step S206. If the menu setting mode end operation has not been received (step S205: N), the process returns to step S205.

  In step S206, the control unit 20 deletes the notification image PA1 when it is projected by the image projection unit 10, and proceeds to step S207.

  In step S207, the control means 20 deletes the menu setting screen by the image projection means 10, returns to the original operation, and ends this operation flow (step S208).

[Operation when the image input terminal is switched]
As shown in FIG. 9, when the switching operation of the image input terminal 6 to which the image signal is input is received by the input switching key operation of the input operation unit 23 while the projector 1 is operating (Step S <b> 301), the control unit 20 The image signal input means 18 is instructed to switch the image input terminal 6 (step S302), and the process proceeds to step S303.

  In step S303, the control unit 20 checks whether the correction amount of the trapezoidal distortion correction is within a predetermined range. If the correction amount is within the predetermined range (step S303: Y), the process proceeds to step S305. If the correction amount is outside the predetermined range (step S303: N), the process proceeds to step S304.

  In step S304, the control unit 20 causes the image projection unit 10 to project a notification image PA1 (see FIGS. 6B and 6C) that notifies that the correction amount exceeds the predetermined range, and causes the step S305 to cause the control unit 20 to project. Transition.

  In step S305, the operation flow ends.

[Operation when a change in the image signal detection state is detected]
As shown in FIG. 9, when the projector 1 is operating, when the image signal detection means 26 detects that the detection state of the image signal input to the image signal input means 18 has changed (step S311), the control means 20 Based on the input state of the image signal, the image projection means 10 projects an input image or an image (see FIG. 6C) indicating that no image signal is input (step S312), and the process proceeds to step S303. . Since step S303 and subsequent steps have been described above, a description thereof will be omitted.

[Operation when correction amount setting change operation is accepted during notification image projection]
As shown in FIG. 10, when the projector 1 projects a notification image PA1 (see FIGS. 6A to 6C) and receives a correction amount setting change operation by the input operation unit 23 (step S401), the control unit 20 sets the correction amount of the trapezoidal distortion correction information 21a to a predetermined value (step S402), and the process proceeds to step S403. Here, the predetermined value is, for example, zero or a predetermined small value.

  In step S403, the control unit 20 instructs the trapezoidal distortion correction unit 15 to execute the trapezoidal distortion correction based on the correction amount set in the trapezoidal distortion correction information 21a. Next, the process proceeds to step S404. If the set correction amount is zero, an image without keystone distortion correction is projected.

  In step S404, the control unit 20 deletes the notification image PA1 by the image projection unit 10 and ends the operation flow (step S405).

According to the embodiment described above, the following effects can be obtained.
According to the projector 1 of the present embodiment, when the correction amount of the trapezoidal distortion correction is not zero, the notification LED 25 notifies the user that the projected image has been corrected for distortion. As a result, it is possible to prevent the user from using the projector 1 without noticing that the distortion has been corrected, and to urge the user to suppress the correction amount of the distortion correction, such as reviewing the installation position of the projector 1.

  In addition, in the menu setting mode for setting the setting items of the projector 1, the notification image PA1 is projected. Thereby, when the menu setting mode is started when the use of the projector 1 is started or when the setting is changed, it is possible to notify the user that the distortion is corrected in the projected image.

  Further, the notification image PA1 is projected when the image input terminal 6 to which the image signal is input is switched. Thus, when the image input terminal 6 for inputting an image signal is switched at the start of use of the projector 1 or when the input is changed, it is possible to notify the user that distortion correction has been performed on the projected image. .

  The notification image PA1 is projected when the detection state of the image signal input to the image input terminal 6 changes. Thereby, when the detection state of the image signal changes due to a change in connection of the video equipment input to the projector 1, it is possible to notify the user that the projected image has been corrected for distortion.

  In addition, by notifying when the correction amount of distortion correction applied to the projected image exceeds the predetermined range, notification is not made if the correction amount is within the predetermined range, but only when the correction amount exceeds the predetermined range. can do. As a result, it is possible to notify the user only when the correction amount for distortion correction becomes large and it is better to review the installation position of the projector 1.

  In addition, when the installation position of the projector 1 cannot be changed, the distortion correction amount can be changed to zero or within a predetermined range by a predetermined operation, and deterioration of the image quality of the projected image can be suppressed. Become.

Moreover, you may change this embodiment as follows.
(Modification 1)
In the embodiment described above, the projector 1 corrects the trapezoidal distortion as the projection distortion. However, in addition to this, a pincushion distortion that is distorted so that the center is depressed with respect to the top and bottom of the image, and a center that swells with respect to the top and bottom of the image. You may make it correct | amend the barrel distortion which distorts.

(Modification 2)
In the above-described embodiment, a notification is made when the correction amount of the trapezoidal distortion correction exceeds a predetermined range, but the notification range is made in multiple stages, for example, when the correction amount is +1 to +5, -1 to -5. When the first notification and the correction amount are +6 or more and −6 or less, the notification method may be changed such as second notification.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 6 ... Image input terminal, 10 ... Image projection means, 11 ... Light source, 12R, 12G, 12B ... Liquid crystal light valve, 13 ... Projection lens, 14 ... Liquid crystal drive means, 15 ... Trapezoid distortion correction means, 16 ... OSD processing means, 17 ... image signal processing means, 18 ... image signal input means, 19 ... angle detection means, 19a ... acceleration sensor, 20 ... control means, 21 ... storage means, 21a ... trapezoidal distortion correction information, 22 ... light source control Means, 23 ... Input operation means, 25 ... Notification LED, 26 ... Image signal detection means, 30 ... Power supply terminal, 31 ... Power supply unit, SC ... Screen, PA1 ... Notification image.

Claims (7)

A projector having an image projection unit that modulates light emitted from a light source according to image information based on an image signal input from an image input terminal and projects the light onto a projection surface,
Correction amount setting means for setting a correction amount for correcting the projection distortion of the projected image projected on the projection surface;
Distortion correction means for executing distortion correction of the projected image based on the correction amount;
Informing means for informing that the distortion correction is performed on the corrected image when the correction amount is not zero;
A projector characterized by comprising: The projector according to claim 1.
The notification means includes
In a menu setting mode for setting setting items of the projector, the projector is notified by projecting a notification image on the projection surface. The projector according to claim 1 or 2,
The projector includes a plurality of the image input terminals,
The notification means includes
When the image input terminal to which the image signal is input is switched, the projector is notified by projecting a notification image on the projection surface. The projector according to any one of claims 1 to 3,
An image signal detecting means for detecting whether an image signal is input to the image input terminal;
The notification means includes
A projector which notifies by projecting a notification image on the projection surface when the detection state of the image signal by the image signal detection means changes. In the projector as described in any one of Claim 1 to 4,
The projector is configured to notify when the correction amount exceeds a predetermined range. The projector according to any one of claims 2 to 5,
An input operation means for receiving an input operation;
The correction amount setting means, when projecting the notification image, changes the correction amount to be zero or within a predetermined range when a predetermined correction amount changing operation is received from the input operation means. Projector featuring. A method for controlling a projector having image projection means for modulating light emitted from a light source according to image information and projecting the light onto a projection surface,
A correction amount setting step for setting a correction amount for correcting the projection distortion of the projected image projected on the projection surface;
A distortion correction step of executing distortion correction of the projected image based on the correction amount;
A notification step of notifying that the distortion correction is performed on the corrected image when the correction amount is not zero;
A projector control method characterized by comprising:

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