JP2013057767A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus that projects an image in an optimum projection size able to maintain satisfactory image quality.SOLUTION: The electronic apparatus comprises: a projecting part 34 that projects a projection image on a projection surface; a measuring part 36 that measures a distance from the projecting part to the projection surface; an information storage part 31 storing a projection optical characteristic for each projection size of a standard screen obtained by projecting projection light in different projection sizes onto a standard screen; a selecting part 20 that selects from the information storage part the projection optical characteristic when the projection light is projected in the same size as a projection size used when projection is carried out at the same projection field angle as the present projection field angle from the same distance as the distance measured by the measuring part; a detecting part 20 that detects the optical characteristic of the projection surface while projection light with the same brightness as projection light used for projection on the standard screen when the projection optical characteristic selected by the selecting part is obtained; and a determination part 20 that determines an optimum projection size on the basis of the projection optical characteristic selected by the selecting part and the optical characteristic detected by the detecting part.

Description

  The present invention relates to an electronic device.

  Conventionally, a projector that can adjust the size of a projected image is known (see, for example, Patent Document 1). According to this projector, various characteristics of the video signal can be adjusted in accordance with the size of the image to be projected.

Japanese Utility Model Publication No. 6-054030

  However, in the projector described above, there are cases where the image quality of the projected image cannot be maintained when various characteristics of the video signal are adjusted in accordance with the size of the projected image.

  An object of the present invention is to provide an electronic device that projects an image with an optimum projection size that can maintain good image quality.

  The electronic apparatus of the present invention projects a projection image on a projection surface, a measurement unit that measures a distance from the projection unit to the projection surface, and a plurality of different projection sizes with respect to a standard screen. An information storage unit for storing projection optical characteristics for each projection size of the standard screen acquired by projecting light, and a projection movie having the same projection angle as the current projection angle from the same distance as measured by the measurement unit A selection unit that selects, from the information storage unit, a projection optical characteristic when the projection light is projected with the same projection size as when projected at a corner, and the projection optical characteristic selected by the selection unit is acquired. A detection unit that detects optical characteristics of the projection surface in a state in which projection light having the same brightness as the projection light projected on the standard screen is projected, and the selection unit selects Characterized in that it comprises a determining unit to determine an optimal projection size based on optical characteristics detected by projection optical properties and the detection unit has.

  According to the electronic apparatus of the present invention, it is possible to project an image with an optimal projection size that can maintain good image quality.

It is a perspective view which shows the projection state of the projector which concerns on 1st Embodiment. 1 is a block diagram showing a system configuration of a projector according to a first embodiment. It is a flowchart which shows the process of the projector which concerns on 1st Embodiment. It is a top view which shows the imaging range of the imaging part in the projector which concerns on 1st Embodiment. It is a side view which shows the imaging range of the imaging part in the projector which concerns on 1st Embodiment. It is a figure which shows the coordinate of the projection surface which detects an optical characteristic with the projector which concerns on 1st Embodiment. It is a flowchart which shows the process of the projector which concerns on 2nd Embodiment. It is a flowchart which shows the process of the projector which concerns on 3rd Embodiment. It is a perspective view which shows the projection state of the projector which concerns on embodiment.

  Hereinafter, with reference to the drawings, an electronic apparatus according to the first embodiment will be described using a projector as an example. FIG. 1 is a perspective view showing a projection state of the projector according to the first embodiment. The projector 2 includes a housing 4 made of metal or plastic. On the back of the housing 4 is an LCD display unit 6 for displaying a message image, etc., which will be described later, a multi-selector 8 for selecting a projection image, and the like. And a start button 12 for starting a process for determining an optimal projection size 11 that can maintain good image quality (hereinafter referred to as a size determination process). Further, on the upper surface of the housing 4, a power switch 14 and a release button 15 for giving an imaging instruction by an imaging unit 24 described later are provided.

  FIG. 2 is a block diagram showing a configuration of the projector 2 according to the first embodiment. The projector 2 includes a CPU 20. The CPU 20 includes a multi selector 8, a PJ button 10, a start button 12, a power switch 14, a release button 15, and the like, and a display control unit 23 that performs display control of the LCD display unit 6. An image pickup unit 24 having an image pickup device for picking up an image of a subject, a storage unit 26 for storing image pickup data output from the image pickup unit 24, a program storage unit 30 for storing a program for setting and controlling projection, etc., standard projection An information storage unit 31 for storing information on optical characteristics for each projection size of the standard screen detected by projecting a white image with a predetermined brightness at a plurality of different projection sizes on the standard screen in the environment, and a projection size A history storage unit 32 for storing the enlarged or reduced information as history information, and an image of a projected image Memory card 33 for storing data, projection 34 for projection an image, and a measuring unit 36 for measuring the distance to the projection plane W from the front surface of the housing 4 are connected. Note that the measuring unit 36 may use a distance measuring unit that measures the distance to the subject when the imaging unit 24 images the subject. Further, the brightness of the white image projected on the standard screen may be the brightness when the projector 2 is normally used in the standard projection environment, and may not be the rated brightness (maximum brightness). Good.

  Here, the projection unit 34 turns on and off the LED light source 46, which is a light source, and adjusts the amount of projection light emitted from the LED light source 46, and the projection control that controls the LCOS 50 that displays the projection image. A portion 52 is provided.

  Next, processing of the projector 2 according to the first embodiment will be described with reference to the flowchart shown in FIG. First, when the projector 2 is installed at a predetermined position and the PJ button 10 is operated, a projection mode is set (step S1). Next, the CPU 20 reads message data such as “Please turn the projector toward the screen” stored in the program storage unit 30, and displays this message on the LCD display unit 6 (step S2).

  Next, the CPU 20 determines whether or not the start button 12 has been operated (step S3). When the start button 12 is operated (step S3: Yes), the CPU 20 starts the size determination process. That is, first, the distance from the front surface of the housing 4 to the projection surface W is measured by the measuring unit 36 (step S4). Then, the CPU 20 drives a lens driving unit (not shown) by the projection control unit 52 to move the projection lens (not shown) in the optical axis direction and projects an image at the current position of the housing 4. The projection angle of the projection unit 34 is adjusted so that the projection size is smaller than the maximum projection size and larger than the minimum projection size when the image is projected at the current position of the housing 4 (step S5). Here, it is preferable that the projection angle is adjusted to a projection angle at which projection can be performed with an intermediate projection size between the maximum projection size and the minimum projection size so that the optimum projection size 11 can be determined quickly.

  Next, the CPU 20 determines the brightness of the standard screen when a white image is projected at the same distance as the current distance from the front surface of the housing 4 to the projection surface W and at the same projection angle as the current projection angle. Information on the minimum value Lm and information on the predetermined threshold value α0 are read from the information storage unit 31 (step S6). Note that the projection performance of the projector 2 is reflected in the brightness of the standard screen when a white image is projected.

  Next, the CPU 20 adjusts the amount of projection light by the power supply control unit 48, and once projects a white image having the same brightness as the white image projected when the information about the brightness of the standard screen is acquired (on the projection surface W) ( Step S7).

  Next, the CPU 20 images the projection surface W by the imaging unit 24 in a state where the white image is projected on the projection surface W. For example, as shown in FIG. 4, when the current projection range when the projector 2 is viewed from above is XP, and when the current projection range when the projector 2 is viewed from the side as shown in FIG. 5 is YP, The CPU 20 images the projection surface W by adjusting the imaging angle of view of the imaging unit 24 so that the imaging range XC matches the current projection range XP and the imaging range YC matches the current projection range YP.

  Here, the adjustment of the imaging angle of view also takes into account the distances DX and DY between the imaging window 40 through which subject light is incident and the projection window 42 through which projection light is emitted. 4 and 5, the distance L indicates the current distance from the front surface of the housing 4 to the projection surface W, and XS and YS indicate the maximum projection range when a projection image is projected at the distance L. ing. XP and YP indicate the projection range of the current projection size 17 (see FIG. 1) when the projection image is projected at the distance L.

  The CPU 20 stores the imaging data output from the imaging unit 24 in the storage unit 26. Next, the CPU 20 reads the imaging data from the storage unit 26, and detects the optical characteristics of the projection surface W in the current projection range from the imaging data (step S8). For example, when the coordinate axis as shown in FIG. 6 is set for the projection plane W, the CPU 20 detects the brightness of the projection plane W in each coordinate (i, j) of the current projection range XP and YP. Here, let Lij be the luminance value detected at an arbitrary coordinate in the current projection range. The luminance value Lij reflects the reflectance of the projection surface W, the illumination state of the projection environment, and the like.

  Next, the CPU 20 extracts the maximum luminance value MAX (Lij) from the luminance values Lij detected at each coordinate (i, j), and determines whether or not the condition shown in Equation 1 is satisfied. Perform (step S9).

MAX (Lij) / Lm ≦ α0 Equation 1
Here, when the condition shown in Formula 1 is satisfied (step S9: Yes), when the projected image is projected with the current projection size 17, the luminance of the coordinate at which the maximum luminance value MAX (Lij) is detected is projected. Expected to have little effect on image quality. For this reason, even if the current projection size 17 is enlarged, the image quality of the projected image can be maintained.

  In this case, the CPU 20 adjusts the projection angle of the projection unit 34 so that a projection size that is one step larger than the current projection size 17 can be projected (step S10). Then, the fact that the current projection size 17 has been enlarged is stored in the history storage unit 32.

  Next, based on the information stored in the history storage unit 32, the CPU 20 determines whether or not the adjustment content of the current projection angle is different from the adjustment content of the previous projection angle (step S11). When the adjustment content of the current projection angle is different from the adjustment content of the previous projection angle (step S11: Yes), that is, the previous current projection size 17 is reduced (enlarged), and the current current projection size 17 is enlarged ( In the case of reduction, the CPU 20 determines the current projection size 17 as the optimum projection size 11. Next, the CPU 20 returns the enlarged projection size to the current projection size 17, reads the image data from the memory card 33, and projects the projection image based on the image data on the projection surface W with the optimum projection size 11. Step S13).

  On the other hand, when the adjustment details of the current projection angle are not different from the adjustment details of the previous projection angle (step S11: No), for example, the previous current projection size 17 is enlarged (reduced), and this time the current projection size is also changed. When 17 is enlarged (reduced), or when the current projection size 17 is enlarged or reduced for the first time this time, the process returns to step S6.

  That is, the CPU 20 reads from the information storage unit 31 information related to the minimum luminance value Lm of the standard screen when a white image having a projection size that is one step larger than the current projection size 17 is projected (step S6). Then, a white image is projected onto the projection surface W with a projection size that is one step larger than the current projection size 17 (step S7), and the optical characteristics of the projection surface W in the projection range of this projection size are detected (step S8). Then, the process of step S9-S11 is repeated.

  Further, when the condition shown in Formula 1 is not satisfied (step S8: No), if a projected image is projected at the current projected size 17, the luminance at the coordinates where MAX (Lij) is detected may affect the image quality of the projected image. There is. For this reason, it may be necessary to maintain the image quality of the projected image by reducing the projection size and enhancing the light collection effect of the projection light.

  In this case, the CPU 20 reads information related to the predetermined threshold α1 from the information storage unit 31, and determines whether or not there is a coordinate that satisfies the condition shown in Formula 2 in the current projection range (step S14). Here, it is assumed that the value of α1 is larger than the value of α0.

α1> Lij / Lm Equation 2
If there is no coordinate that satisfies the condition shown in Formula 2 in the current projection range (step S14: No), the CPU 20 adjusts the projection angle so that it can be projected with a projection size that is one step smaller than the current projection size 17 ( The process proceeds to step S17) and step S10.

  On the other hand, if there is a coordinate that satisfies the condition shown in Formula 2 in the current projection range (step S14: Yes), the CPU 20 calculates the area A of the region that satisfies α0 <Lij / Lm <α1 in the current projection range. . Further, when a white image is projected on the standard screen with the current projection size 17, information regarding the feature area Ak of the area where the reflected light affects the image quality of the projected image is read from the information storage unit 31 (step S15). Here, the area A is not the total area of a plurality of areas, but the area of one connected area.

  Next, the CPU 20 determines whether or not the condition shown in Formula 3 is satisfied based on the area A and the feature area Ak (step S16).

A ≦ Ak Equation 3
When the condition shown in Formula 3 is satisfied (step S16: Yes), the process proceeds to step S9. On the other hand, when the condition shown in Formula 3 is not satisfied (step S16: No), the process proceeds to step S17.

  According to the projector 2 according to the first embodiment, the optical characteristics of the standard screen when a white image is projected in the standard projection environment and the projection surface W detected by projecting the white image in the current environment. Since the optimum projection size 11 is determined by comparing the optical characteristics with each other and repeatedly changing the projection size based on the comparison result, the projection image can be projected with the optimum projection size capable of maintaining good image quality. . In addition, the optimum projection size 11 can be quickly determined by adjusting the projection angle and starting the size determination process so that projection can be performed with an intermediate projection size between the maximum projection size and the minimum projection size. Can do.

  Next, a projector according to a second embodiment will be described. It should be noted that the projector according to the second embodiment uses the information regarding the brightness of the standard screen when the white image is projected at a projection size that is one step larger than the current projection size 17 in the size determination process. 17 is determined to be enlarged or reduced. Therefore, a detailed description of the same configuration as that of the first embodiment is omitted, and only different portions will be described. Further, the same components as those in the first embodiment will be described with the same reference numerals.

  FIG. 7 is a diagram illustrating processing of the projector according to the second embodiment. First, when the projector 2 is installed at a predetermined position and the PJ button 10 is operated, a projection mode is set (step S21). Next, the CPU 20 reads image data of a message such as “Please turn the projector toward the screen” stored in the program storage unit 30 and displays an image based on the image data on the LCD display unit 6 ( Step S22).

  Next, the CPU 20 determines whether or not the start button 12 has been operated (step S23). When the start button 12 is operated (step S23: Yes), the CPU 20 starts the size determination process. That is, first, the distance from the front surface of the housing 4 to the projection surface W is measured by the measuring unit 36 (step S24). A projection size that is smaller than the maximum projection size when the image is projected at the current position of the casing 4 and larger than the minimum projection size when the image is projected at the position of the current casing 4 (for example, the maximum projection size). The projection angle of the projection unit 34 is adjusted so that projection can be performed with a projection size intermediate between the size and the minimum projection size (step S25).

  Next, the CPU 20 relates to the brightness of the standard screen when a white image is projected at the same distance as the current distance from the front surface of the housing 4 to the projection surface W and at the same projection angle as the current projection angle. Information and information related to the predetermined threshold value α3 are read from the information storage unit 31 (step S26). Next, information on the luminance value Lpij at a position corresponding to each coordinate (i, j) of the current projection range is extracted from information on the luminance of the standard screen.

  Next, the CPU 20 adjusts the amount of projection light by the power supply control unit 48, and once projects a white image having the same brightness as the white image projected when the information about the brightness of the standard screen is acquired (on the projection surface W) ( Step S27). Then, the imaging unit 24 images the current projection range (see FIGS. 4 and 5) on the projection surface W, and the imaging data output from the imaging unit 24 is stored in the storage unit 26.

  Next, the CPU 20 reads the imaging data from the storage unit 26, and detects the optical characteristics of the projection surface W in the current projection range based on the imaging data (step S28). For example, when the coordinate axis as shown in FIG. 6 is set on the projection plane W, the CPU 20 detects the luminance at each coordinate (i, j) in the current projection range. Here, let Lij be the luminance value detected at an arbitrary coordinate in the current projection range.

  Next, the CPU 20 determines whether or not there is a coordinate satisfying the condition shown in Formula 4 in the current projection range (step S29).

Lij / Lpij ≦ α3 Equation 4
If there is a coordinate that satisfies the condition shown in Equation 4 in the current projection range (step S29: Yes), the CPU 20 relates to the brightness of the standard screen when a white image is projected with a projection size that is one step larger than the current projection size 17. Information is read from the information storage unit 31. Then, from this information, the brightness value Lpij3k of the standard screen at the position corresponding to each coordinate (i, j) of the current projection range is extracted. Next, the CPU 20 calculates MAX (Lij / Lpij), which is the maximum value of Lij / Lpij, using the luminance value Lij and the luminance value Lpij, and determines the calculated value as the threshold value α3k (step S30).

  Next, the CPU 20 determines whether or not there is a coordinate that satisfies the condition shown in Formula 5 in the current projection range (step S31).

Lij / Lpij3k ≦ α3k Equation 5
When there is a coordinate that satisfies the condition shown in Formula 5 in the current projection range (step S31: Yes), the CPU 20 sets the projection angle of the projection unit 34 so that it can be projected at a projection size that is one step larger than the current projection size 17. Adjust (step S32). Then, the fact that the current projection size 17 has been enlarged is stored in the history storage unit 32. Since the processing in steps S33 to S35 is the same as the processing in steps S11 to 13 in the first embodiment, description thereof is omitted.

  On the other hand, when there is no coordinate that satisfies the condition shown in Formula 5 in the current projection range (Step S31: No), or when there is no coordinate that satisfies the condition shown in Formula 4 in the current projection range (Step S29: No). ), The CPU 20 reads information related to the predetermined threshold α4 from the information storage unit 31, and determines whether or not there is a coordinate satisfying the condition shown in Equation 6 in the current projection range (step S36). Here, it is assumed that the value of α4 is larger than the value of α3.

α4> Lij / Lpij Equation 6
If there is no coordinate that satisfies the condition shown in Equation 6 in the current projection range (step S36: No), the CPU 20 sets the projection angle of the projection unit 34 so that it can be projected with a projection size that is one step smaller than the current projection size 17. Adjust (step S39).

  On the other hand, if there is a coordinate that satisfies the condition shown in Equation 6 in the current projection range (step S36: Yes), the CPU 20 calculates an area A of the region that satisfies α3 <Lij / Lpij <α4 in the current projection range. To do. Further, when a white image is projected on the standard screen at the current projection size 17, information on the feature area Ak of the area where the reflected light affects the image quality of the projected image is read from the information storage unit 31 (step S37). Next, based on the area A and the feature area Ak, it is determined whether or not the condition shown in Expression 7 is satisfied (step S38).

A ≦ Ak Equation 7
If the condition shown in Equation 7 is satisfied (step S38: Yes), the process proceeds to step S31. When the condition shown in Equation 7 is not satisfied (step S38: No), the CPU 20 adjusts the projection angle of the projection unit 34 so that the projection size can be projected by one step smaller than the current projection size 17 (step S39).

  According to the projector according to the second embodiment, the current projection size 17 is enlarged or reduced using the information on the brightness of the standard screen when a white image is projected with a projection size one step larger than the current projection size 17. Therefore, the accuracy of the size determination process can be improved.

  Next, a projector according to a third embodiment will be described. Note that the projector according to the third embodiment is configured to determine whether to enlarge or reduce the current projection size 17 based on one mathematical expression in the size determination process. Therefore, a detailed description of the same configuration as that of the first embodiment is omitted, and only different portions will be described. Further, the same components as those in the first embodiment will be described with the same reference numerals.

  FIG. 8 is a diagram illustrating processing of the projector according to the third embodiment. First, when the projector 2 is installed at a predetermined position and the PJ button 10 is operated, a projection mode is set (step S41). Next, the CPU 20 reads out message data such as “Please turn the projector toward the screen” stored in the program storage unit 30, and displays this message on the LCD display unit 6 (step S42).

  Next, the CPU 20 determines whether or not the start button 12 has been operated (step S43). When the start button 12 is operated (step S43: Yes), the CPU 20 starts the size determination process. That is, first, the distance from the front surface of the housing 4 to the projection surface W is measured by the measuring unit 36 (step S44). A projection size that is smaller than the maximum projection size when the image is projected at the current position of the casing 4 and larger than the minimum projection size when the image is projected at the position of the current casing 4 (for example, the maximum projection size). The projection angle of the projection unit 34 is adjusted so that projection can be performed with a projection size intermediate between the size and the minimum projection size (step S45).

  Next, the CPU 20 projects the luminance distribution feature value Lc when a white image is projected at the same distance as the current distance from the front surface of the housing 4 to the projection surface W and at the same projection angle as the current projection angle. And information on the predetermined threshold α5 are read from the information storage unit 31 (step S46). The luminance distribution feature value Lc is a parameter obtained by synthesizing the value of the ratio of the area of the area that affects the image quality of the projected image to the area of the projection range and the luminance of the standard screen.

  Next, the CPU 20 adjusts the amount of projection light by the power supply control unit 48, and once projects a white image having the same brightness as the white image projected when the information about the brightness of the standard screen is acquired (on the projection surface W) ( Step S47). Then, the imaging unit 24 images the current projection range (see FIGS. 4 and 5) on the projection surface W, and the imaging data output from the imaging unit 24 is stored in the storage unit 26.

  Next, the CPU 20 reads the imaging data from the storage unit 26, and detects the optical characteristics of the projection surface W in the current projection range based on the imaging data (step S48). For example, when the coordinate axis as shown in FIG. 6 is set on the projection plane W, the CPU 20 detects the luminance at each coordinate (i, j) in the current projection range. Here, it is assumed that the luminance value detected at an arbitrary coordinate in the current projection range is Lijc.

  Next, the CPU 20 extracts the maximum luminance value MAX (Lijc) from the luminance values Lijc detected at each coordinate (i, j), and determines whether or not the condition shown in Equation 8 is satisfied. (Step S49).

MAX (Lijc) / Lc ≦ α5 Equation 8
When the condition shown in Formula 8 is satisfied (step S49: Yes), the CPU 20 adjusts the projection angle of the projection unit 34 so that the projection size is larger than the current projection size 17 (step S50). On the other hand, when the condition shown in Expression 8 is not satisfied (step S49: No), the projection angle of the projection unit 34 is adjusted so that the projection size can be projected at a level smaller than the current projection size 17. (Step S51).

  Since the processing in steps S52 to S54 is the same as the processing in steps S11 to 13 in the first embodiment, description thereof will be omitted.

  According to the projector 2 according to the third embodiment, the size determination process is performed in order to determine whether to enlarge or reduce the current projection size 17 based on one mathematical expression by using the luminance distribution feature value Lc. The processing speed can be improved.

  In the above-described embodiment, the imaging unit 24 captures an image, and the imaging data output from the imaging unit 24 is used to detect the optical characteristics of the projection surface W. However, the detection unit includes a luminance sensor or the like. And the optical characteristic of the projection surface W may be directly detected by the detection unit. Thereby, the optical characteristic of the projection surface W can be detected without using the imaging unit 24.

  In the above-described embodiment, the case where the projection unit 34 includes the zoom projection optical system and the projection angle is adjusted in the size determination process is described as an example. However, the projection unit 34 is a single-focus projection optical system. You may make it provide. In this case, by displaying a message such as “Move the projector forward” or “Move the projector backward” in the size determination process on the LCD display unit 6, the current projection size 17 is displayed to the operator. May be changed. In this case, as shown in FIG. 9, an instruction mark 16 for instructing whether to enlarge or reduce the current projection size 17 may be projected onto the projection surface W. In addition, a voice output unit may be provided to give an instruction by voice.

  In the above embodiment, the color characteristics of the standard screen for each projection size detected by projecting a red image, a green image, and a blue image with a plurality of different projection sizes on the standard screen in the standard projection environment. The information regarding the information storage part 31 may be memorize | stored. In this case, for example, in the size determination process, the CPU 20 stores information on the color characteristics of the standard screen and information on the predetermined threshold when the red image, the green image, and the blue image are projected at the current projection size 17. Read from 31. Next, the CPU 20 detects the color characteristic RGBij of the projection surface W at each coordinate (i, j) of the current projection range. Here, in the color characteristic RGBij, R represents the color characteristic of the red component, G represents the color characteristic of the green component, and B represents the color characteristic of the blue component. In the above-described embodiment, the standard screen color characteristics and threshold values read from the information storage unit 31 and the color characteristics RGBij of the projection surface W at each coordinate (i, j) of the current projection range are used. A size determination process similar to the size determination process may be performed. Thereby, the optimal projection size 11 can be determined so that the color unevenness of the projection surface W is not conspicuous.

  In the above-described embodiment, the maximum projection size 11 may be determined using the image characteristics of the projection image. For example, the CPU 20 reads information on the optical characteristics of the standard screen and a predetermined threshold value when a white image is projected with the current projection size 17 from the information storage unit 31, and detects the optical characteristics of the projection surface W in the current projection range. . Next, the image data of the image projected on the projection surface W is read from the memory card 33, and the image characteristics of the projected image are detected from the image data. Then, the optimal projection size 11 may be determined using the optical characteristics and threshold values of the standard screen read from the information storage unit 31, the optical characteristics of the projection surface W in the current projection range, and the image characteristics. Thereby, the optimal projection size 11 can be determined so that each projected image can be projected with good image quality.

  In the above-described embodiment, the current projection size 17 is determined as the optimum projection size 11 (see step S12 in FIG. 3), but a projection size other than the current projection size 17 is designated as the optimum projection size 11. You may decide. For example, in the size determination process, it is assumed that the projection angle of the projection unit 34 has been adjusted so that a projection size that is one step larger (smaller) than the current projection size 17 can be projected (see step S10 in FIG. 3). When the adjustment details of the current projection angle are different from the adjustment details of the previous projection angle (see step S11 in FIG. 3), the CPU 20 sets the projection size obtained by further expanding (reducing) the current projection size 17. The optimum projection size 11 may be determined.

  In the above-described embodiment, when the imaging unit 24 captures the projection surface W, a range including the current projection range XP (YC) (see FIGS. 4 and 5) (for example, the maximum projection range XS (YS)). )) May be imaged. Then, based on the current distance from the front surface of the housing 4 to the projection surface W and the current projection angle, pixels in the area corresponding to the current projection range are extracted from the pixels constituting the imaging data, The optical characteristics of the projection surface W in the projection range may be detected. Further, by recognizing the contrast in the imaging data, pixels in a region corresponding to the current projection range may be extracted, and the optical characteristics of the projection surface W in the current projection range may be detected.

  In the embodiment described above, the optical characteristics of predetermined spots on the projection surface W, for example, five spots such as the four corners and the center of the projection surface W may be detected. Thereby, the processing speed of the size determination process can be improved.

  In the above-described embodiment, the information related to the optical characteristics of the standard screen stored in the information storage unit 31 may be information acquired by actual measurement or information acquired by simulation.

  In the above-described embodiment, the measurement method of the measurement unit 36 is not specified, but the distance from the front surface of the housing 4 to the projection surface W is measured even when the projection surface W has low luminance. If possible, measurement methods such as a laser distance meter and an ultrasonic distance meter are not limited.

  DESCRIPTION OF SYMBOLS 2 ... Projector, 4 ... Housing | casing, 6 ... LCD display part, 11 ... Maximum projection size, 17 ... Current projection size, 16 ... Instruction mark, 20 ... CPU, 22 ... Operation part, 23 ... Display control part, 24 ... Imaging , 26 ... storage unit, 30 ... program storage unit, 31 ... information storage unit, 32 ... history storage unit, 33 ... memory card, 34 ... projection unit, 36 ... measurement unit

Claims (7)

A projection unit that projects projected images onto a projection surface;
A measurement unit that measures the distance from the projection unit to the projection surface;
An information storage unit for storing the projection optical characteristics for each projection size of the standard screen obtained by projecting projection light with a plurality of different projection sizes on the standard screen;
Projection optical characteristics when the projection light is projected with the same projection size as the projection size when the projection angle is the same as the current projection angle from the same distance measured by the measurement unit. A selection unit for selecting from the information storage unit;
A detection unit that detects the optical characteristics of the projection surface in a state in which projection light having the same brightness as the projection light projected on the standard screen is projected when the projection optical characteristic selected by the selection unit is acquired; ,
An electronic apparatus comprising: a determining unit that determines an optimal projection size based on the projection optical characteristics selected by the selection unit and the optical characteristics detected by the detection unit.   2. The electronic apparatus according to claim 1, wherein a projection size when the selection unit first performs selection is an intermediate projection size between a maximum projection size and a minimum projection size. A determination unit for determining whether to enlarge or reduce the projection size at the time of selection by the selection unit using the projection optical characteristic selected by the selection unit and the optical characteristic detected by the detection unit;
The electronic device according to claim 1, wherein the determination unit determines an optimum projection size while repeatedly expanding and reducing the projection size based on the determination by the determination unit.   The electronic apparatus according to claim 1, wherein the optical characteristic and the projection optical characteristic are at least one of luminance and color.   5. The projection optical characteristic according to claim 1, wherein the projection optical characteristic is a projection optical characteristic detected by projecting a white image onto the standard screen in a standard projection environment. Electronics. An imaging unit for imaging the projection surface;
The electronic device according to claim 1, wherein the detection unit detects an optical characteristic of the projection surface based on imaging data output from the imaging unit. The projection unit includes a zoom control unit that adjusts a projection angle.
The electronic apparatus according to claim 1, wherein the zoom control unit enlarges or reduces the projection size by adjusting the projection angle.

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