Image display apparatus

【0001】

[Technical field to which the invention belongs]

The present invention relates to switching control of an image displayed by an image display device.

【0002】

[Conventional technology]

Projectors (projection-type display devices) that project and display images are widely used in various presentations. The projector is a presentation data (hereinafter referred to as "presentation tool") prepared in advance by executing software for supporting the presentation (hereinafter referred to as "presentation tool") on a personal computer (hereinafter referred to as "PC"). Hereinafter, the image represented by the image data is reproduced and displayed in "presentation data"). As a presentation tool, PowerPoint (trademark) of Microsoft Corporation is often used.

【0003】

In recent years, as described above, a projector (hereinafter referred to as a "projector with a player") has been developed that can execute a presentation using only a projector without using a PC that functions as an image reproduction device (player). Has been done. The projector with a player has an interface capable of communicating with a memory card such as a PC card, and can display an image represented by image data included in the presentation data stored in the memory card.

【0004】

The mounted player is not a PC that executes PowerPoint, but a device that limits the function to the reproduction of the image represented by the image data included in the presentation data stored in the memory card. For example, this player displays an image represented by image data stored in a memory card in JPEG or BMP format as one slide for each image.

【0005】

By the way, PowerPoint can set various display effects (hereinafter, also referred to as "screen switching effect") in switching from slide to slide in order to increase the attention of the presentation to be executed. The display effect is the image that is actually displayed (Image C) when the screen is switched from the displayed image (referred to as Image A) to the image to be displayed next (referred to as Image B). It is obtained by how to generate.). Specifically, it is obtained by setting either one of the pixel a included in the image A and the pixel b included in the image B, or the calculated value of the pixel a and the pixel b as the pixel c of the image C. Such display effects include, for example, animation effects such as fade-in, fade-out, slide-in, wipe, and blind.

【0006】

The projector with a player is provided with hardware in the mounted player for selecting image data to be output for each pixel based on mask data equal to the size of the output image data. As a result, the same display effect as when using PowerPoint is realized.

【0007】

[Problems to be Solved by the Invention]

However, in the case of a conventional projector with a player, mask data equal to the size of the image data is required, and a large-capacity memory area for storing the mask data is required. Further, in order to realize one display effect, a plurality of mask data are usually required, and the required memory area increases accordingly. Further, the higher the resolution of the image, the larger the required memory area. Therefore, as the required memory area increases, the number of memory accesses required for rewriting the mask data also increases. For this reason, the load on the CPU that executes memory access also increases, and there is a problem that high-speed processing is difficult. It should be noted that such a problem is a problem common to image display devices that realize the same display effect.

【0008】

The present invention has been made to solve the above-mentioned problems in the prior art, and an object of the present invention is to provide a technique capable of realizing a process related to screen switching at a higher speed than in the prior art.

【0009】

[Means for solving problems and their actions / effects]

In order to solve at least a part of the above-mentioned problems, the image display device of the present invention includes an image display unit and an image reproduction unit that generates display image data displayed by the image display unit, and the image reproduction unit is provided. The unit is a predetermined image selection mask when the image displayed on the image display unit is switched from the first image to an image in which the second image is displayed in at least a part of the area of the first image. It has an image switching control unit that generates the display image data by performing an operation on the first and second images using the above, and the image switching control unit has the first image and the second image. A storage unit for storing an image and a group selection mask having an image area smaller than at least a part of the area, and the group selection mask in the selection mask having an image area having the same size as the at least a part of the area. It is characterized by having a selection mask conversion unit for conversion.

【0010】

In the image display device, a group selection mask having an image area smaller than at least a part of the area of the first image on which the second image is displayed has an image area of the same size as at least a part of the area. The display image data can be generated by converting to a selection mask and performing an operation on the first and second images using the converted selection mask. At this time, the area of the storage unit for storing the basic selection mask can be made smaller than the area for storing the selection mask in the conventional case, so that the processing related to screen switching can be realized at a higher speed than in the conventional case. It is possible.

【0011】

Here, "performing the calculation on the first and second images" means not only mixing the first and second images, but also selecting one of the images in at least a part of the area. Including that.

【0012】

The selection mask conversion unit can generate the selection mask by enlarging or reducing the group selection mask. Further, the selection mask conversion unit can also generate the selection mask by using the group selection mask as one block data and repeatedly processing the block data two-dimensionally. Further, the selection mask can be generated by using the enlargement / reduction process and the iterative process together.

【0013】

In the image display device, the image reproduction unit includes an interface capable of reading data stored in a portable recording medium, and at least one of the image data representing the first and second images is connected to the interface. It is preferable to read from the connected recording medium.

【0014】

In this way, the image data stored in the recording medium can be read out and displayed on the image display unit.

【0015】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the image display device according to the present invention will be described with reference to the drawings based on the following examples.

【0016】

A. Projector Configuration: FIG. 1 is a block diagram showing a schematic configuration of a projector as an embodiment of the present invention. The projector 10 includes a projector unit 20 that functions as an image display unit and an image reproduction unit 30.

【0017】

The projector unit 20 calculates the first CPU 200 that executes a predetermined program to control each block of the projector unit 20, the first ROM 202 that stores the program executed by the first CPU 200, and the first CPU 200. It is equipped with a first RAM 204 that temporarily stores results and data. The first CPU 200, the first ROM 202, and the first RAM 204 are connected via the memory bus 206.

【0018】

The projector unit 20 further includes an image signal conversion circuit (VSCNV) 210, an audio control circuit (SDCTL) 220, a liquid crystal drive circuit (LCDDRV) 230, a light source control circuit (LSCTL) 240, and a projection optical system 260. I have. The image signal conversion circuit 210, the audio control circuit 220, the liquid crystal drive circuit 230, and the light source control circuit 240 are connected to the first CPU 200 via the first system bus 208.

【0019】

The image signal conversion circuit 210 realizes functions such as an analog-to-digital conversion function, a decoding function, a synchronous signal separation function, and an image processing function. That is, the image signal conversion circuit 210 converts the analog image signal input from the external video signal input terminal 212 into digital image data, and synchronizes the converted digital image data with the synchronization signal in the image signal conversion circuit 210. Write to the frame memory (VRAM) 211, or read the digital image data written to this frame memory 211. As the analog image signal, for example, an RGB signal output from a personal computer, a composite image signal output from a video tape recorder, or the like is input. When the analog image signal is a composite image signal, the image signal conversion circuit 210 demodulates the composite image signal and separates it into a component image signal and a synchronization signal composed of three RGB color signals, and the component image signal. To digital image data. When the analog image signal is an RGB signal output from a personal computer, it is originally input as a component image signal and the synchronization signal is also input separately, so that separation processing is not required. Converts a component image signal into digital image data.

【0020】

Further, digital image data output from the image reproduction unit 30 is also input to the image signal conversion circuit 210. In such a case, since the synchronization signal is originally input as a digital image signal and is supplied separately, analog-to-digital conversion processing and separation processing are unnecessary.

【0021】

The image signal conversion circuit 210 includes a selection circuit (not shown), and selects a plurality of video signals input from the external video signal input terminal 212 and one of the digital image data input from the image reproduction unit 30. Select and store in frame memory 211. The selection of the analog image signal and the digital image signal is performed according to a command from an external input device such as a remote controller (not shown). Alternatively, it is performed according to a command from the second CPU 300 of the image reproduction unit 30 described later.

【0022】

The voice control circuit 220 drives the speaker 224 by a drive signal generated based on a voice signal or sound data transmitted from the external voice signal input terminal 222 or the sound source 360 in accordance with a command from the first CPU 200. The audio control circuit 220 also has a selection circuit (not shown) like the image signal conversion circuit 210, and among a plurality of audio signals input from the external audio signal input terminal 222 and sound data input from the sound source 360. Select one from. The selection of the audio signal or the sound data is performed according to the selection of the image signal and the digital image signal supplied from the image reproduction unit 30.

【0023】

The liquid crystal panel drive circuit (LCD drive circuit) 230 receives the image data processed by the image signal conversion circuit 210, drives the liquid crystal panel (LCD) 232 according to the received image data, and illuminates the light from the light source 242. Modulate light. The illumination light modulated by the LCD 232 is projected onto a projected surface, for example, a projection screen, via a projection optical system 260 including a lens. A light source control circuit 240 is connected to the light source 242, and the light source control circuit 240 controls on / off and the amount of light of the light source 242 according to a command from the first CPU 200.

【0024】

The image reproduction unit 30 has a second CPU 300 that executes a predetermined program to control each block of the image reproduction unit 30, a second ROM 302 that stores a program executed by the second CPU 300, and a second CPU 300. It is equipped with a second RAM 304 that temporarily stores the calculation results and data of. The second CPU 300, the second ROM 302, and the second RAM 304 are connected via the memory bus 306.

【0025】

The image reproduction unit 30 further includes a screen switching controller (VSWCTL) 310, a PCMCIA interface controller (PCMCIA I / F CTL) 340, and a sound source 360. Each block is connected to the second CPU 300 via the second system bus 308.

【0026】

The PCMCIA interface controller (hereinafter simply abbreviated as "PCMCIA controller") 340 is a controller that transfers data to a connected external device in accordance with the PCMCIA standard and transfers data from the external device to the image playback unit 30. is there. The PCMCIA controller 340 is connected to a PC card 40 installed in a card slot (not shown). The PC card 40 is a small, removable, portable recording medium that complies with the PCMCIA standard. The portable small recording medium is not limited to the PC card, and various memory cards can be applied. In this case, a controller corresponding to the applied memory card is provided in place of the PCMCIA controller 340.

【0027】

The screen switching controller 310 executes the presentation tool stored in the second ROM 302 to display the image data included in the presentation data read from the PC card 40 based on the command from the second CPU 300. It is supplied to the image signal conversion circuit 210. The screen switching controller 310 will be described later.

【0028】

The sound source 360 generates sound data based on a command from the second CPU 300 and supplies it to the voice control circuit 220 of the projector unit 20.

【0029】

The image reproduction unit 30 is also connected to the first system bus 208 of the projector unit 20 via a bus buffer 330 connected to the second system bus 308. The first CPU 200 and the second CPU 300 can communicate with each other via the bus buffer 330. A circuit using dual port memory, an I / O interface, or the like can be used for the bus buffer 330.

【0030】

B. Configuration of screen switching controller 310: FIG. 2 is a block diagram showing a configuration example of the screen switching controller 310. The screen switching controller 310 includes an image developing unit 311 as a storage unit of the present invention, an image buffer unit 312, a mask conversion unit 313 as a selection data conversion unit, a screen switching unit (VSW) 314, and a processing control unit 315. And have.

【0031】

The processing control unit 315 is connected to the second system bus 308 and controls the operation of each block constituting the screen switching controller 310.

【0032】

The image development unit 311 is composed of general RAM. The image data read from the PC card 40 is temporarily stored in the image development unit 311. FIG. 2 shows a case where the image data of the image A displayed first (image A data) and the image data of the image B displayed next (image B data) are stored.

【0033】

If the image data contained in the presentation data stored in the PC card 40 is compressed image data in a format such as JPEG, the second CPU 300 expands the image data into BMP format image data and expands the image. Stored in part 311.

【0034】

Further, the second CPU 300 generates the corresponding mask data according to the screen switching effect to be executed, and also accesses the image development unit 311 to store the generated mask data.

【0035】

In the following, the operation of each block of the screen switching controller 310 will be described by taking the case where the image A is switched to the image B and displayed as an example.

【0036】

Generally, the RAM constituting the image development unit 311 cannot read the image A data, the image B data, and the mask data in parallel. Therefore, the image A data, the image B data, and the mask data are read out in chronological order from the image developing unit 311 in the order of, for example, 1 mask data, 2 image A data, and 3 image B data. .. The image buffer unit 312 buffers the image A data read earlier, and adjusts the timing of outputting the image A data and the image B data to the screen switching unit 314. The image buffer unit 312 can be realized by a general buffer circuit that adjusts the timing of image data.

【0037】

It is also possible to omit the image buffer unit 312 by configuring the image development unit 311 with three RAMs in which the image A data, the image B data, and the mask data can be controlled independently.

【0038】

The mask conversion unit 313 converts the mask data as the basic selection mask of the present invention having a size smaller than the image data into the conversion mask data as the selection mask of the present invention having the same size as the image data. Mask data generation and conversion depends on the type of screen switching effect (display effect) realized by screen switching, for example, the type of animation effect (slide-in, blind, checker wipe, etc.) that can be realized with PowerPoint. Is executed.

【0039】

The conversion mask data is data in which each pixel of the image data has a one-to-one correspondence, and is data indicating which of the two types of images is selected for each pixel. For example, the data "1" represents the selection of the first image and the data "0" represents the selection of the second image.

【0040】

The screen switching unit 314 acquires the conversion mask data from the mask conversion unit 313 and the image A data and the image B data from the image buffer unit 312 for each pixel of the image data output to the image signal conversion circuit 210. Then, the image data (image C data) in which the image data corresponding to the conversion mask data is selected for each pixel is output. As a result, the projector unit 20 displays an image corresponding to the conversion mask data. Therefore, when the image A is switched to the image B and displayed, the desired screen switching effect can be obtained by preparing the mask data corresponding to the desired screen switching effect and executing the screen switching.

【0041】

C. Specific example of screen switching: In the following, the operation of the screen switching controller 310 when switching image A to image B will be described using a specific example. FIG. 3 is an explanatory diagram showing an example of an image A before switching and an image B after switching. FIG. 4 is an explanatory diagram showing an example of mask data stored in the image development unit 311.

【0042】

For ease of explanation, the size of the display screen is 128 × 96 pixels, and as shown in FIGS. 3 (A) and 3 (B), the image A and the image B are the same size as the display screen.

【0043】

As the mask data, as shown in FIGS. 4 (A) to 4 (E), five mask data (32 × 32 pixels) are used. FIGS. 4 (A) to 4 (E) show each mask data as image information corresponding to the screen. The white pixel area represents the area where the data is "1" and indicates the pixel area (area 1) for selecting the first image, and the black pixel area represents the area where the data is "0" and is the second. The pixel area (area 2) for selecting the image of is shown. Therefore, the mask 1 in FIG. 4 (A) shows the mask data for selecting the first image. In the mask 2 of FIG. 4B, the upper right and lower left 8 × 16 pixel area 2 selects the second image, and the other area 1 shows the mask data for selecting the first image. In the mask 3 of FIG. 4 (C), the second image is selected for the area 2 of the upper right half (16 × 16 pixels) and the lower left half (16 × 16 pixels), and the upper left half (16 × 16 pixels) and the lower right. The half (16 × 16 pixels) area 1 shows the mask data for selecting the first image. In the mask 4 of FIG. 4 (D), the upper left and lower right 8 × 16 pixel area 1 shows the mask data for selecting the first image, and the other area 2 shows the mask data for selecting the second image. Mask 5 in FIG. 4 (E) shows mask data for selecting the second image.

【0044】

These mask data are stored in the image development unit 311 by the second CPU 300. However, all the mask data of FIGS. 4 (A) to 4 (E) may be stored in advance, or may be stored in order according to the screen switching process.

【0045】

C1. Screen switching example 1: FIG. 5 is an explanatory diagram showing screen switching example 1. The figure on the left side of FIG. 5 shows the conversion mask data corresponding to the display screen, and the figure on the right side shows the display image.

【0046】

In this screen switching example 1, when switching from the display of the image A shown in FIG. 5 (A) to the display of the image B shown in FIG. 5 (E), the display area of the image B is displayed by 32 pixels in the horizontal direction from the right side of the screen. Shows an example of switching in which is increasing in order.

【0047】

As shown in FIGS. 5 (A) to 5 (E), the conversion mask data used is such that the second area for selecting the second image is on the right side of the first area for selecting the first image. It is increasing in order from 32 pixels in the horizontal direction.

【0048】

Each conversion mask data of FIGS. 5 (A) to 5 (E) is obtained as shown below. FIG. 6 is an explanatory diagram showing a process of obtaining the conversion mask data of FIG. 5 (B). The conversion mask data in FIG. 5 (B) is the mask data shown in FIG. 6 (A) (mask 2 shown in FIG. 4 (B)), which is quadrupled in the horizontal direction and in the vertical direction as shown in FIG. 6 (B). It can be obtained by using the upper half of the data multiplied by 6. The other conversion mask data in Fig. 5 (A), (C), (D), and (E) are also enlarged in the same way as the mask data in Fig. 4 (A), (C), (D), and (E). Can be obtained.

【0049】

By using the image A as the first image and the image B as the second image in the screen switching unit 314, from the image A as shown in the right figure of FIGS. 5 (A) to 5 (E). When switching to the display of image B, the display area of image B can be switched in order from the right side of the screen by 32 pixels in the horizontal direction.

【0050】

In addition, in FIGS. 5 (A) to 5 (E), the image A displayed on the screen corresponding to the area 1 is deleted in order from the right side of the image A as the right side of the area 1 decreases. However, as the area 1 decreases, the image A may be slid in order from the left side to be erased. Further, the image B displayed on the screen corresponding to the area 2 is the image B as the left side of the area 2 increases.<u style="single">From the right</u>Although they are displayed in order, they may be displayed by sliding in order from the left side of the image B as the area 2 increases. Such deformation can be realized by adjusting the reading positions of the images A and B read from the image developing unit 311. In this way, the screen switching effect (display effect) obtained by screen switching using mask data can be further enhanced.

【0051】

Since FIG. 5A shows only the image A and FIG. 5E shows only the image B, it is not always necessary to select the image using the conversion mask data in the screen switching unit 314. The image selection may be fixed in the image switching unit 314 regardless of the content of the conversion mask data. This modification is the same in the following screen switching example.

【0052】

C2. Screen switching example 2: FIG. 7 is an explanatory diagram showing screen switching example 2. The figure on the left side of FIG. 7 shows an example of conversion mask data, and the figure on the right side shows an example of a display image.

【0053】

In this screen switching example 2, when the display of the image A shown in FIG. 7 (A) is switched to the display of the image B shown in FIG. 7 (E), the image has a checkered pattern as shown in FIG. 7 (C). After the state where A and the image B are displayed, as shown in FIGS. 7 (B) to 7 (D), the area where the image A is displayed decreases and the area where the image B is displayed increases. An example of switching is shown.

【0054】

Each conversion mask data of FIGS. 7 (A) to 7 (E) is obtained as shown below. FIG. 8 is an explanatory diagram showing a process of obtaining the conversion mask data of FIG. 7B. The conversion mask data of FIG. 7 (B) is the mask data shown in FIG. 8 (A) (mask 2 shown in FIG. 4 (B)) in the vertical direction four times in the horizontal direction as shown in FIG. 8 (B). It can be obtained by repeating the process two-dimensionally three times. The other conversion mask data in Fig. 7 (A), (C), (D), and (E) are also iteratively processed in the same way as the mask data in Fig. 4 (A), (C), (D), and (E). Can be obtained.

【0055】

In FIGS. 7 (A) to 7 (E), the image A displayed on the screen corresponding to the area 1 of the conversion mask data and the image B displayed on the screen corresponding to the area 2 are the image switching example 1. As in the case described in the modified example of, the image may be an image in which the reading positions of the image A and the image B read from the image developing unit 311 are adjusted.

【0056】

C3. Screen switching example 3: FIG. 9 is an explanatory diagram showing a screen switching example 3. The figure on the left side of FIG. 9 shows an example of conversion mask data, and the figure on the right side shows an example of a display image.

【0057】

The screen switching example 3 shows a case where the display of the image A shown in FIG. 9 (A) is switched to the display of the image B shown in FIG. 9 (E) by using the same conversion mask data as the screen switching example 1. However, the second image displayed on the screen corresponding to the area 2 of the conversion mask data is characteristic in the middle of switching the screen, that is, in the case of FIGS. 9 (B) to 9 (D). .. Specifically, in the screen switching example 1, the image B is displayed in the area 2, whereas in the screen switching example 3 of this example, the mixed image A &amp; B of the image A and the image B is displayed in the area 2. To.

【0058】

The mixed image A &amp; B is an image in which image A and image B are mixed at a predetermined mixing ratio ((image A: image B = Ka: Kb, Ka + Kb = 1)). Each mixed image A &amp; B in D) has a different mixing ratio. Specifically, the mixed image A &amp; B in FIG. 9 (B) has Ka = 3/4 and Kb = 1/4, and FIG. 9 (B). The mixed image A &amp; B in C) shows an image with Ka = 2/4, Kb = 2/4, and the mixed image A &amp; B in FIG. 9 (D) shows an image with Ka = 1/4, Kb = 3/4. Note that the image B in FIG. 9 (E) corresponds to the mixed image A &amp; B of Ka = 0, Kb = 1. Here, the image A may be a mixed image of Ka = 1, Kb = 0. Image B may be a source image that is not a mixed image.

【0059】

As shown in FIGS. 9 (B) to 9 (D), by changing the mixing ratio of the mixed image A &amp; B displayed in the area 2, the display of the mixed image A &amp; B becomes lighter in order, and the display of the mixed image A &amp; B becomes lighter in order. The display is darkened. As a result, it is possible to obtain an effect that the image B emerges from the image A. When the image A is a single-color image, the image can be faded in. When the image B is a single color, the fade-out of the image can be realized.

【0060】

Therefore, in the image switching example 3 of this example, in addition to being able to obtain the effect that the display area of the image B to be switched and displayed increases in order from the right side of the screen, as in the image switching example 1. Therefore, it is possible to obtain the effect that the image B emerges from the image A by the mixed image A &amp; B as described above.

【0061】

C4. Screen switching example 4: The above screen switching examples 1 to 3 explain the case where the size of the image A before switching and the size of the image B after switching are equal to the size of the display screen. Even when is smaller than the size of the display screen, the image switching as shown below is possible. In the following, the case where the image A is the 128 × 96 pixel image shown in FIG. 10 (A) and the image B is the 64 × 48 pixel image shown in FIG. 10 (B) will be described as an example. ..

【0062】

FIG. 11 is an explanatory diagram showing a screen switching example 4. The figure on the left side of FIG. 11 shows an example of conversion mask data, and the figure on the right side shows an example of a display image. In this screen switching example 4, when the image B is combined and displayed at an arbitrary position of the image A shown in FIG. 11 (A) as shown in FIG. 11 (E), the conversion mask is used for the portion where the image B is displayed. As shown in FIGS. 11 (B) to 11 (D) using data, an example of switching screens in order is shown.

【0063】

FIG. 12 is an explanatory diagram showing an area in which the image B is displayed. The area where the image B is displayed can be obtained in advance as coordinate data (x, y) on the display screen. That is, if the area in which the image B is to be displayed is set, the coordinate data of the image B on the display screen is obtained accordingly. In this embodiment, the upper left of the display screen is set as the origin (0,0), and the upper left (x1, y1) and lower right (x2, y2) areas are set as the display area of the image B. ..

【0064】

In the area where the image B is not displayed on the display screen, that is, in the area of x &lt;x1 and x&gt; x2 and y &lt;y1 and y&gt; y2, the image A is displayed regardless of the switching display of the image B. Therefore, this area is an area (non-screen switching area) in which screen switching does not need to be performed. Therefore, the screen switching unit 314 of FIG. 2 is set so as not to switch the image according to the conversion mask data in this non-screen switching area. Further, in the area where the switching display of the image B is performed (screen switching area), that is, in the area of x1 x x2 and y1 y y2, the screen switching unit 314 switches the image according to the conversion mask data. Is set to do. It should be noted that such a setting of the screen switching unit 324 is performed by the processing control unit 315.

【0065】

The conversion mask data of FIGS. 11 (B) to 11 (E) are obtained as shown below. FIG. 13 is an explanatory diagram showing a process of obtaining the conversion mask data of FIG. 11 (B). Similar to the screen switching example 2, the screen switching example 4 shows a case where the mask data is repeatedly arranged two-dimensionally using the converted mask data. However, while the size of image B is 64 x 48 pixels, the mask data is 32 x 32 pixels as shown in FIG. 4, so simply repeat the arrangement to obtain the conversion mask data. Can't. Therefore, the conversion mask data is obtained by combining the enlargement / reduction processing and the iterative processing of the mask data. Specifically, first, the mask data shown in FIG. 13 (A) (mask 2 shown in FIG. 4 (B)) is two-dimensionally displayed twice in the horizontal and vertical directions as shown in FIG. 13 (B). Repeatedly arrange processing. Then, as shown in FIG. 13 (C), the conversion mask data in FIG. 11 (B) can be obtained by multiplying the intermediate mask data shown in FIG. 13 (B) by 3/4 in the vertical direction. .. The conversion mask data of other FIGS. 11 (C) and 11 (D) can be obtained in the same manner. The order of the repetitive arrangement process and the enlargement / reduction process may be reversed.

【0066】

It should be noted that, after the image A is switched and displayed as a composite image of the image A and the image B (hereinafter referred to as "image C"), the image A may be further switched and displayed as the image D (not shown). Be done. In such a case, simply, the image development unit 311 of FIG. 2 is provided with an area for storing the image D, and the image buffer unit 312 is provided with a buffer circuit for adjusting the timing of outputting the image D to the image switching unit 314. Therefore, it is conceivable that the image switching unit 314 similarly switches and displays the image C to the image D. Alternatively, the image C is used as the image before switching, the image D is used as the image after switching, and the image data of the image C and the image D are newly stored in the image developing unit 311 so that the image C is switched and displayed on the image D. It is also possible to make it.

【0067】

As described in this screen switching example 4, the image before switching and the image after switching do not necessarily have to be the same size. Even when the image after switching is smaller than the image before switching, the screen can be switched using the mask data.

【0068】

Further, the conversion mask data can be obtained by combining these processes as well as the enlargement / reduction process and the iterative array process. Thereby, the conversion mask data corresponding to the screen switching effect to be executed can be obtained by using the mask data having a size smaller than the conversion mask data, and various screen switching effects can be realized.

【0069】

As described above, in the projector 10 of the present embodiment, mask data smaller than the size of the image data is converted into conversion mask data equal to the size of the image data. Then, by switching the screen display from the image A to the image B using the conversion mask data, it is possible to realize the screen switching according to the conversion mask data.

【0070】

At this time, since the mask data stored in the image developing unit 311 is mask data having a size smaller than that of the image data, the mask data can be used as compared with the case where the mask data having the same size as the image data is used as in the conventional case. There is an advantage that the memory area for storing is reduced. In addition, the load on the second CPU 300 required to store the mask data in the image development unit 311 can be reduced. As a result, a desired display effect (screen switching effect) can be obtained by performing high-speed processing for screen switching.

【0071】

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

【0072】

D1. Modification 1: FIG. 14 is a block diagram showing a modification of the projector 10. In this projector 10A, the second CPU 300, ROM 302, RAM 304, and bus buffer 330 of the projector 10 are omitted, and the PCMCIA controller 340, the screen switching controller 310, and the sound source 360 are connected to the first system bus 208. The configuration is shown. In this projector 10A, the first CPU 200, ROM 202, and RAM 204 can be provided with the functions of the second CPU 300, ROM 302, and RAM 304, and the configuration of the device can be simplified.

【0073】

In the projector having the simplified configuration as described above, the screen switching controller 310 may be provided inside the image signal conversion circuit 210.

【0074】

Further, the image signal input from the external video signal input terminal 212 may be converted into digital image data and then input to the screen switching controller 310. By doing so, the screen switching effect is applied not only to the image represented by the image data included in the presentation data read from the PC card but also to the image represented by the image signal input from the external video signal input terminal 212. Can be given.

【0075】

D2. Modification 2: The above embodiment is described by taking a projector as an example, but the present invention is not limited to this, and can be applied to an image display device having an image reproduction device having an image reproduction unit.

[Simple explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a projector as an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a screen switching controller 310.

FIG. 3 is an explanatory diagram showing an example of an image A before switching and an image B after switching.

FIG. 4 is an explanatory diagram showing an example of mask data stored in the image development unit 311.

FIG. 5 is an explanatory diagram showing a screen switching example 1.

FIG. 6 is an explanatory diagram showing a process of obtaining the conversion mask data of FIG. 5 (B).

FIG. 7 is an explanatory diagram showing a screen switching example 2.

FIG. 8 is an explanatory diagram showing a process of obtaining the conversion mask data of FIG. 7B.

FIG. 9 is an explanatory diagram showing a screen switching example 3.

FIG. 10 is an explanatory diagram showing an example of an image A before switching and an image B after switching.

FIG. 11 is an explanatory diagram showing a screen switching example 4.

FIG. 12 is an explanatory diagram showing an area in which image B is displayed.

FIG. 13 is an explanatory diagram showing a process of obtaining the conversion mask data of FIG. 11 (B).

FIG. 14 is a block diagram showing a modified example of the projector 10.

[Explanation of symbols]

10 ... Projector 10A ... Projector 20 ... Projector 30 ... Image playback 200 ... CPU202 ... ROM204 ... RAM206 ... Memory bus 208 ... System bus 210 .. Image signal conversion circuit 211 ... Frame memory 212 ... External video signal input terminal 220 ... Audio control circuit 222 ... External audio signal input terminal 224 ... Speaker 230 ... Liquid crystal drive circuit 240. .. Light source control circuit 242 ... Light source 260 ... Projector optical system 300 ... CPU302 ... ROM304 ... RAM306 ... Memory bus 308 ... System bus 310 ... Screen switching controller 311. .. Image development unit 312 ... Image buffer unit 313 ... Mask conversion unit 314 ... Screen switching unit 315 ... Processing control unit 320 ... Voice control circuit 330 ... Bus buffer 360 ... sound source