JP2008268624A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of displaying character information such as time without hiding an image which should be displayed. <P>SOLUTION: When a user operates a character synthesis key to instruct display of character information (character synthesis), an image signal processing part sets a character area 12t having height Ht capable of displaying character strings for one line on an upper part of a pixel area 12a and compensates image data so that an input image Gi is settled in height Hg of the remaining area (image area 12g). A synthesis processing part generates character image data presenting the character information (date and time) based on an instruction of a control part and synthesizes the generated character image data with image data inputted from the image signal processing part in order to form a character image Gt in a character area 12t. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector that projects an image according to an input image signal.

  There are cases in which it is desired to check the time during presentation or video viewing using a projector. However, when the projector is used with the room darkened, it is difficult to see the clock in the room and it is difficult to check the time. In addition, even when the room is not so dark, the presentation progress and video viewing may be interrupted by checking the time. Patent Document 1 proposes a projector capable of displaying time in an image to be displayed. According to this projector, since the time is displayed in the image, it is possible to confirm the time without removing the line of sight from the image regardless of the brightness of the room.

JP-A-9-261568

However, displaying the time in the image hides a part of the image to be displayed by the time, and thus has a problem that it becomes annoying when the time display is not required. ing. Even if the projector main unit or remote control is equipped with a button for switching between time display and non-display, this button must be operated each time the time is confirmed, which makes the user feel bothersome. Will end up.
SUMMARY An advantage of some aspects of the invention is that it provides a projector capable of displaying character information such as time without hiding an image to be displayed.

  The projector of the present invention includes a light source, a light modulation device that forms an image by modulating light emitted from the light source, a projection optical system that projects an image formed by the light modulation device, and the light modulation device An image signal processing unit that forms an input image based on an input image signal in a partial area of the image, and a character display that forms a character image representing character information outside the partial area of the light modulation device And a section.

  According to this projector, since the character display unit forms a character image outside the input image, the character information is displayed outside the projected input image. Therefore, character information such as time can be displayed without hiding the image to be displayed.

  In the projector, the image signal processing unit includes a trapezoidal distortion correction unit that reduces the input image formed in the light modulation device in order to correct the trapezoidal distortion that occurs when tilt projection is performed, and the character display unit In this case, it is preferable that the character image is formed in a surplus area generated by the keystone distortion correcting unit reducing the input image.

  According to this projector, the trapezoidal distortion correction unit reduces the input image to correct the trapezoidal distortion, and the character display unit forms a character image in a surplus area generated by the reduction of the input image by the trapezoidal distortion correction unit. . For this reason, it is not necessary to reduce the input image again in order to secure an area for displaying the character information, and therefore it is possible to suppress deterioration of the input image (degradation of image quality) due to the reduction.

  In this projector, the image signal processing unit may reduce the input image to provide a necessary surplus area when there is no surplus area capable of forming the character image outside the partial area. Also good.

  According to this projector, when there is no surplus area in which a character image can be formed, the image signal processing unit reduces the input image so as to provide a necessary surplus area. Therefore, the character is always outside the input image. An image can be displayed.

  In this projector, the character display unit may form the character image in the surplus area only when the surplus area where the character image can be formed is outside the partial area.

  According to this projector, since it is not necessary to reduce the input image only for displaying the character information, it is possible to suppress deterioration of the input image (degradation of image quality) due to the reduction.

  In this projector, it is preferable that the character information is date information representing at least one of a date and a time.

  According to this projector, since the date and time are displayed outside the input image, it is not necessary to look at the calendar or the clock during the presentation or video viewing.

Hereinafter, a projector according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a projector according to the present embodiment, and shows how an image is projected on a screen.
As shown in FIG. 1, the projector 1 projects an image (input image Gi) corresponding to an image signal input from an external image supply device 2 such as a personal computer onto a screen SC or the like, and outside the input image Gi. A character image Gt representing character information (date and time information) such as date and time can be projected upward. That is, the image (projected image Ga) projected from the projector 1 includes the input image Gi and the character image Gt.

FIG. 2 is a block diagram illustrating a schematic configuration of the projector according to the present embodiment.
As shown in FIG. 2, the projector 1 includes an image projection unit 10 that projects an image, a control unit 20, an input operation unit 21, a clock unit 22, an image signal input unit 31, and an image signal processing unit 32. And a synthesis processing unit 34.

  The image projection unit 10 includes a light source 11 including a discharge-type light source lamp such as an ultra-high pressure mercury lamp and a metal halide lamp, and a liquid crystal light valve 12 as a light modulation device that modulates light emitted from the light source 11 to form an image. A projection lens 13 serving as a projection optical system for enlarging and projecting an image formed by the liquid crystal light valve 12 onto a screen SC and the like, and a light valve driving unit 14 for driving the liquid crystal light valve 12 are provided.

  The liquid crystal light valve 12 is configured by a liquid crystal panel in which liquid crystal is sealed between a pair of transparent substrates. The liquid crystal light valve 12 is formed with a rectangular pixel region 12a composed of a plurality of pixels Px arranged in a matrix, and a driving voltage can be applied to the liquid crystal for each pixel Px. When a driving voltage corresponding to an image signal is applied to each pixel Px of the liquid crystal light valve 12 by driving the light valve driving unit 14, light emitted from the light source 11 is liquid crystal with different light transmittance for each pixel Px. An image (image light) corresponding to the image signal is transmitted through the light valve 12 and projected onto the screen SC or the like by the projection lens 13.

  Although not shown in the figure, the image projection unit 10 includes three liquid crystal light valves 12 for light of the three primary colors red (R), green (G), and blue (B). Yes. The light emitted from the light source 11 is separated into the three color lights by a light separation optical system (not shown), and then enters the liquid crystal light valve 12 for each color light. The image light of each color transmitted through the liquid crystal light valve 12 is synthesized for each pixel by a light synthesis optical system (such as a dichroic prism) (not shown), and is projected from the projection lens 13 as image light representing a color image.

  The control unit 20 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) including a flash memory, a RAM (Random Access Memory) used for temporary storage of various data, and the like (none of which are shown). It functions as a computer. The control unit 20 performs overall control of the operation of the projector 1 by the CPU operating according to a control program stored in the ROM.

  The input operation unit 21 includes a plurality of keys for giving various instructions to the projector 1. Keys provided in the input operation unit 21 include a power key for turning on / off the power, a menu key for performing various settings, a trapezoidal distortion correction key for instructing correction of trapezoidal distortion, and a character image Gt. There are character synthesis keys for switching between display and non-display. When the user operates the input operation unit 21, the input operation unit 21 outputs an operation signal corresponding to the operation content of the user to the control unit 20. The input operation unit 21 may be configured using a remote control (not shown) capable of remote operation. In this case, the remote control transmits an infrared operation signal corresponding to the user's operation content, and a remote control signal receiving unit (not shown) receives this and transmits it to the control unit 20.

  The clock unit 22 is composed of, for example, a real-time clock or a secondary battery for backup power supply (both not shown), and holds and updates the current time (hour / minute) and date (month / day). Do. The clock unit 22 outputs date and time information representing the time and date to the control unit 20 every time the time and date are updated.

  Various types of image signals are input to the image signal input unit 31 from an external image supply device 2 such as a personal computer or a video reproduction device. The image signal input unit 31 generates digital image data representing the input image Gi based on the input image signal. This image data includes a plurality of pixel values corresponding to all the pixels Px of each liquid crystal light valve 12. The pixel value determines the light transmittance of the corresponding pixel Px, and the intensity (gradation) of light emitted from each pixel Px is defined by this pixel value. The image signal input unit 31 outputs the generated image data to the image signal processing unit 32.

  The image signal processing unit 32 performs various image processing such as deformation (enlargement and reduction) of the input image Gi and correction of color tone on the input image data based on an instruction from the control unit 20, and the processed image Data is output to the composition processing unit 34. In addition, the image signal processing unit 32 includes a trapezoidal distortion correction unit 33, and when performing tilt projection, that is, when projecting an image with the projector 1 tilted with respect to the screen SC, the input image Gi. Correction (trapezoidal distortion correction) for suppressing distortion (trapezoidal distortion) that expands in the tilt direction can be applied to the image data. When the user operates the trapezoidal distortion correction key of the input operation unit 21, the control unit 20 instructs the image signal processing unit 32 to perform the trapezoidal distortion correction by the trapezoidal distortion correction unit 33. When the image signal processing unit 32 receives the above instruction from the control unit 20, the trapezoidal distortion correction unit 33 performs pixel value decimation from the image data and performs correction to reduce the input image Gi in the direction toward the tilt.

  The composition processing unit 34 performs processing for compositing and displaying the character image Gt representing character information based on an instruction from the control unit 20, and corresponds to the character display unit of the present invention. The composition processing unit 34 includes a memory (not shown) and stores image data (font data) representing a font of characters. When the user operates the character composition key of the input operation unit 21, the control unit 20 instructs the composition processing unit 34 to display the character image Gt. When receiving the above instruction from the control unit 20, the composition processing unit 34 reads out necessary font data from the memory and generates character image data representing the character image Gt. Thereafter, the composition processing unit 34 adds the character image data to the image data input from the image signal processing unit 32 so that the character image Gt is formed at a predetermined position of the projection image Ga (outside above the input image Gi). Synthesize.

  In this embodiment, date and time are displayed as character information. The control unit 20 generates text data representing the date and time based on the date / time information obtained from the clock unit 22 and outputs the text data to the synthesis processing unit 34. The composition processing unit 34 generates character image data based on the text data and synthesizes the image data.

  The composition processing unit 34 outputs the combined image data to the light valve driving unit 14. Note that when there is no instruction to display the character image Gt from the control unit 20, the composition processing unit 34 outputs the image data output from the image signal processing unit 32 to the light valve driving unit 14 as it is.

  When the light valve driving unit 14 drives the liquid crystal light valve 12 according to the input image data, that is, the pixel value for each pixel Px, the liquid crystal light valve 12 forms an image corresponding to the image data in the pixel region 12a. An image is projected from the projection lens 13 onto the screen SC.

Next, trapezoidal distortion correction by the trapezoidal distortion correction unit 33 will be described with reference to FIGS. 3 and 4.
FIGS. 3A to 3E and FIGS. 4A to 4D are explanatory diagrams for explaining the trapezoidal distortion correction. FIGS. 3A to 3E illustrate the trapezoidal distortion correction. The figure which shows the state which has not performed, FIG. 4 (a)-(d) is a figure which shows the state which performed the trapezoid distortion correction | amendment. 3A is a front view of the liquid crystal light valve 12, FIG. 3B is a side view showing how the projector 1 performs horizontal projection, and FIG. 3C is a screen at that time. It is a front view which shows the projection image Ga displayed on SC. FIG. 3D is a side view showing a state where the projector 1 performs the projection, and FIG. 3E is a front view showing the projection image Ga displayed on the screen SC at that time. 4A and 4C are front views of the liquid crystal light valve 12, and FIGS. 4B and 4D are front views showing a projected image Ga displayed on the screen SC when tilting projection is performed. FIG.

  3 and 4, the horizontal direction toward the liquid crystal light valve 12 is ± x direction, the vertical direction is ± y direction, the horizontal direction toward the screen SC is ± X direction, and the vertical direction is ± Y direction. To do. 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 valve 12, respectively. For example, the pixels on the upper right (+ x, + y side) of the pixel region 12a are transmitted. The light is projected on the upper right (+ X, + Y side) of the screen SC. 3 and 4, the grid pattern shown in the pixel area 12a and the projected image Ga indicates the correspondence between the image formed in the pixel area 12a and the projected image Ga projected on the screen SC. Therefore, it is a supplementary line, and does not mean that such a pattern is actually displayed. For simplicity of explanation, FIGS. 3 and 4 show an example in which only the input image Gi is displayed without displaying the character image Gt.

  As shown in FIG. 3A, when the keystone correction is not performed and the character image Gt is not displayed, the liquid crystal light valve 12 forms the input image Gi over 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. 3B and 3C, when the projector 1 is installed horizontally and performs projection without tilting on the screen SC, the projection image Ga (input image Gi) is: A rectangular shape having the same aspect ratio (aspect ratio) as that of the pixel region 12a is projected onto the screen SC with almost no distortion. On the other hand, as shown in FIGS. 3D and 3E, when the projector 1 is installed at an inclination angle θ with respect to the installation surface and is projected upward (+ Y direction), the projection is performed. The image Ga (input image Gi) is enlarged in the ± X direction and the + Y direction and distorted in a trapezoidal shape as it goes in the tilt direction (+ Y direction).

  When the control unit 20 instructs the image signal processing unit 32 to perform trapezoidal distortion correction, the image signal processing unit 32 thins out the pixel values from the input image data, and compared with the case where the correction is not performed. The correction is performed so that Gi is reduced in the ± X direction and the ± Y direction as it goes in the tilt direction (+ Y direction). Specifically, as shown in FIG. 4A, the pixel region 12a of the liquid crystal light valve 12 has a trapezoidal shape in the opposite direction that can cancel the trapezoidal distortion, that is, a height lower than the pixel region 12a. An image forming area 12i having a shape in which the lateral width (the dimension in the ± x direction) is reduced toward the direction (+ y direction) is set. Next, in order to form the input image Gi in the set image forming area 12i, the trapezoidal distortion correcting unit 33 thins out more pixel values from the image data at positions where the degree of enlargement by tilt projection is higher. The image data is corrected so that the light transmittance of each pixel Px included in the surplus area 12n generated by thinning (image reduction) is reduced outside the area 12i. As a result, as shown in FIG. 4B, the distortion of the input image Gi due to tilt projection is corrected, and the region Gn in the projection image Ga corresponding to the surplus region 12n is hardly irradiated with light. The input 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.

  Further, the user can correct the trapezoidal distortion with a plurality of correction amounts by operating the keystone correction key. When the user operates the trapezoidal distortion correction key to specify the correction amount, the control unit 20 outputs correction information representing the specified correction amount to the image signal processing unit 32, and the image signal processing unit 32 outputs the correction information. The height Hi of the image forming region 12i and the length Wi of the shorter base (the upper base in this embodiment) are determined based on the above. For this reason, when the tilt angle θ (see FIG. 3D) is large and the distortion of the projected image Ga is large, the user has a small tilt angle θ as shown in FIGS. 4C and 4D. By specifying the correction amount so that the height Hi and the upper base length Wi of the image forming area 12i are smaller than the case, the correction according to the inclination angle θ of the projector 1 can be performed.

Next, the operation of the projector 1 when displaying the character image Gt will be described.
5 to 9 are explanatory diagrams for explaining the operation when displaying the character image Gt. FIGS. 5 and 6A to 9B are views of the liquid crystal light valve 12. A front view is shown. Moreover, (c) of FIGS. 6-9 is a front view which shows the projection image Ga displayed on the screen SC.

  When the user operates the character composition key to instruct the display of character information (character composition), the control unit 20 notifies the image signal processing unit 32 that there has been an instruction for character composition and also performs composition processing. Text data representing character information (date and time) to be synthesized is output to the unit 34 to instruct character synthesis.

  When the image signal processing unit 32 receives the above notification from the control unit 20, as shown in FIG. 5, the image signal processing unit 32 displays a character region 12t having a height Ht capable of displaying a character string for one line on the upper portion of the pixel region 12a. Then, the image data is corrected so that the input image Gi falls within the height Hg of the remaining area (hereinafter referred to as the image area 12g).

  Specifically, the image signal processing unit 32 determines whether or not the height Hi (see FIG. 4) of the image forming area 12i when the character composition key is operated exceeds the height Hg of the image area 12g. That is, it is determined whether or not the height Hn (see FIG. 4) of the surplus area 12n above the image forming area 12i is lower than the height Ht of the character area 12t. As a result, when the height Hi of the image forming area 12i exceeds the height Hg of the image area 12g, that is, when the height Hn of the surplus area 12n is lower than the height Ht of the character area 12t. The image signal processing unit 32 reduces the image forming area 12i and sets a new image forming area 12j (see FIGS. 6 and 7) that fits in the image area 12g.

  For example, when the keystone key is operated and the trapezoidal distortion correction is not performed and the input image Gi is formed in the entire pixel area 12a (see FIG. 3A), the image forming area 12i. Is equal to the height of the pixel area 12a and exceeds the height Hg of the image area 12g. Therefore, as shown in FIG. 6A, the image signal processing unit 32 reduces the image forming area 12i so far and sets a new rectangular image forming area 12j in the image area 12g. Then, the image signal processing unit 32 corrects the input image Gi by reducing the pixel values substantially uniformly in order to form the input image Gi in the new image forming area 12j for the image data input thereafter. And a correction for minimizing the light transmittance of the surplus area 12n (including the character area 12t) outside the image forming area 12j.

  Further, when trapezoidal distortion correction is performed when the character composition key is operated, and the height Hi of the image forming area 12i exceeds the height Hg of the image area 12g (see FIG. 4A). As shown in FIG. 7A, the image signal processing unit 32 reduces the image forming area 12i so far and sets a new trapezoidal image forming area 12j that fits in the image area 12g. Thereafter, the image signal processing unit 32 performs trapezoidal distortion correction by the trapezoidal distortion correcting unit 33 on the image data so as to form the input image Gi in the new image forming region 12j.

  As shown in FIG. 8A, when the trapezoidal distortion correction is performed when the character composition key is operated, the height Hi of the image forming area 12i is equal to or less than the height Hg of the image area 12g. In this case, it is not necessary to reduce the image forming area 12i. That is, the image signal processing unit 32 continues the trapezoidal distortion correction by the trapezoidal distortion correcting unit 33 so as to form the input image Gi in the image forming area 12i so far for the image data input thereafter.

  On the other hand, when receiving an instruction for character synthesis from the control unit 20, the synthesis processing unit 34 generates character image data based on the text data input from the control unit 20, and FIG. 6B, FIG. 7B, As shown in FIG. 8B, the generated character image data is combined with the image data input from the image signal processing unit 32 to form a character image Gt in the character region 12t.

  When the light valve driving unit 14 drives the liquid crystal light valve 12 in accordance with the image data input from the composition processing unit 34, the liquid crystal light valve 12 forms an image in which the input image Gi and the character image Gt are combined. An image is projected on the screen SC (see FIGS. 6C, 7C, and 8C).

  In FIGS. 7C and 8C, the character information is distorted due to the trapezoidal distortion. However, as shown in FIG. 9B, the trapezoidal distortion correction is performed on the character image data to be synthesized. If the character image Gt is distorted in the reverse direction in advance, it is possible to suppress distortion of the displayed character information as shown in FIG.

  When the character composition key is operated again by the user in a state where character composition is being performed, the control unit 20 instructs the image signal processing unit 32 and the composition processing unit 34 to end the character composition. When receiving the above instruction, the image signal processing unit 32 returns to the state in which the input image Gi is formed in the original image forming area 12i.

As described above, according to the projector 1 of the present embodiment, the following effects can be obtained.
(1) According to the projector 1 of the present embodiment, since the composition processing unit 34 synthesizes character image data so as to form the character image Gt outside the input image Gi, the character information (date and time) is It will be displayed outside the projected input image Gi. For this reason, it is possible to display the character information without hiding the image to be displayed, that is, the input image Gi.

  (2) According to the projector 1 of the present embodiment, the trapezoidal distortion correction unit 33 reduces the input image Gi toward the tilt direction, and the composition processing unit 34 is generated by the reduction of the input image Gi by the trapezoidal distortion correction unit 33. A character image Gt is formed in the surplus area 12n. Therefore, when trapezoidal distortion correction is performed with a predetermined correction amount, it is not necessary to reduce the input image Gi again in order to secure an area for displaying character information. (Decrease)) can be suppressed.

  (3) According to the projector 1 of this embodiment, the image signal processing unit 32 reduces the input image Gi when the surplus area 12n in which the character image Gt can be formed is not present outside the input image Gi. Since the surplus area 12n is provided, the character image Gt can always be displayed outside the input image Gi.

  (4) According to the projector 1 of the present embodiment, since the date and time are displayed outside the input image Gi, there is no need to look at the calendar or the clock during presentation or video appreciation.

(Modification)
Moreover, you may change the embodiment of this invention as follows.
In the above-described embodiment, when the user instructs to synthesize character information, the character information is always displayed. However, as a result of reducing the image forming area 12i to correct the trapezoidal distortion, It is also possible to display the character information only when there is a surplus area 12n having a size necessary for forming the character image Gt. For example, the image signal processing unit 32 notifies the control unit 20 of the height Hi of the image forming region 12i, and the composition processing is performed only when the control unit 20 has the height Hi equal to or less than the height Hg of the image region 12g. The unit 34 may be instructed to synthesize character information. In this case, since it is not necessary to reduce the input image Gi just to display the character information, it is possible to suppress deterioration (degradation in image quality) of the input image Gi due to the reduction.

  In the embodiment, the character area 12t is provided above the image area 12g. However, the position of the character area 12t may be any of up, down, left, and right as long as it is outside the image area 12g. Further, the character region 12t is not limited to one place, and may be provided at a plurality of places.

  In the embodiment, the date and time are displayed as the character information. However, the character information is not limited to the above, and for example, a manufacturer name or various messages may be displayed. It is also possible to adopt a configuration in which the user can arbitrarily set the character information to be displayed.

  In the embodiment, when the aspect ratio of the input image Gi is different from the aspect ratio of the pixel area 12a, as shown in FIG. 10, the character image Gt is formed in the surplus area 12n generated outside the image forming area 12i. What should I do? When the height of the surplus area 12n is smaller than the height necessary for forming the character image Gt, that is, the height Ht of the character area 12t (see FIG. 5), the image forming area 12i is reduced. Or move it.

  In the above-described embodiment, an example in which the projector 1 performs projection in the + Y direction has been described. However, the present invention is also applied to projection in other directions (−Y direction and ± X direction). Is possible.

  In the above embodiment, the transmissive liquid crystal light valve 12 is used as the light modulator, but a reflective light modulator such as a reflective liquid crystal light valve can also be used. In addition, it is possible to use a micromirror array device that modulates light emitted from a light source by controlling the emission direction of incident light for each micromirror as a pixel.

  In the embodiment, the light source 11 is constituted by a discharge light source lamp, but a solid light source such as an LED (Light Emitting Diode) light source or other light sources may be used.

1 is a perspective view showing a projector according to an embodiment of the invention. FIG. 2 is a block diagram showing a schematic configuration of a projector. (A)-(e) is explanatory drawing for demonstrating the trapezoid distortion correction by a trapezoid distortion correction part, and is a figure which shows the state which has not performed the trapezoid distortion correction with respect to image data. (A)-(d) is explanatory drawing for demonstrating the trapezoid distortion correction by a trapezoid distortion correction part, and is a figure which shows the state which performed the trapezoid distortion correction with respect to image data. It is explanatory drawing for demonstrating the operation | movement at the time of displaying a character image, and is a front view of a liquid crystal light valve. (A)-(c) is explanatory drawing for demonstrating the operation | movement at the time of displaying a character image, (a), (b) is a front view of a liquid crystal light valve, (c) is on a screen. The front view which shows the projection image displayed. (A)-(c) is explanatory drawing for demonstrating the operation | movement at the time of displaying a character image, (a), (b) is a front view of a liquid crystal light valve, (c) is on a screen. The front view which shows the projection image displayed. (A)-(c) is explanatory drawing for demonstrating the operation | movement at the time of displaying a character image, (a), (b) is a front view of a liquid crystal light valve, (c) is on a screen. The front view which shows the projection image displayed. (A)-(c) is explanatory drawing for demonstrating the operation | movement at the time of displaying a character image, (a), (b) is a front view of a liquid crystal light valve, (c) is on a screen. The front view which shows the projection image displayed. It is explanatory drawing for demonstrating operation | movement when the aspect ratio of an input image differs from the aspect ratio of a pixel area | region, and is a front view of a liquid crystal light valve.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Image supply apparatus, 10 ... Image projection part, 11 ... Light source, 12 ... Liquid crystal light valve, 12a ... Pixel area, 12t ... Character area, 12g ... Image area, 12i, 12j ... Image formation area, 12n DESCRIPTION OF SYMBOLS Excess area | region, 13 ... Projection lens, 14 ... Light valve drive part, 20 ... Control part, 21 ... Input operation part, 22 ... Clock part, 31 ... Image signal input part, 32 ... Image signal processing part, 33 ... Trapezoid distortion Correction unit, 34 ... composite processing unit, Ga ... projected image, Gt ... character image, Gi ... input image, Px ... pixel, SC ... screen.

Claims (5)

A light source;
A light modulation device that modulates the light emitted from the light source to form an image;
A projection optical system for projecting an image formed by the light modulation device;
An image signal processing unit for forming an input image based on an input image signal in a partial area of the light modulation device;
A character display unit for forming a character image representing character information outside the partial region of the light modulation device;
A projector comprising: The projector according to claim 1,
The image signal processing unit includes a trapezoidal distortion correction unit that reduces the input image to be formed in the light modulation device in order to correct the trapezoidal distortion that occurs when tilting projection is performed,
The projector, wherein the character display unit causes the trapezoidal distortion correction unit to form the character image in a surplus area generated by reducing the input image. The projector according to claim 2,
The image signal processing unit is provided with a necessary surplus area by reducing the input image when there is no surplus area capable of forming the character image outside the partial area. The projector according to claim 2,
The projector is characterized in that the character display unit forms the character image in the surplus area only when the surplus area where the character image can be formed is outside the partial area. The projector according to any one of claims 1 to 4,
The projector is characterized in that the character information is date and time information representing at least one of a date and a time.

Images