Portable projection device

Abstract

The present invention provides a portable projection device capable of smoothly changing the position of a projected image, even when provided with a camera shake compensation function.　A projection state maintenance processing unit (16) performs a projection state maintenance process for suppressing changes in the position, size, or shape of a projected image relative to a projection surface SC, on the basis of the result of detecting a first relative change in the position or orientation of a projector (11) with respect to the projection surface SC. A second detection unit (17) detects, as a second relative change, a relative change in the position of the projected image or the size of the projected image on the projection surface SC. When it is assessed from the second relative change that a termination condition of the projection state maintenance process is satisfied, the projection state maintenance process is terminated.

Description

Portable projection device

[0001] The present invention relates to a portable projection device.

[0002] In Patent Document 1, in a camera with a projector capable of handheld projection and placement projection, in the case of handheld shooting, there is a handheld mode for turning on the anti-shake processing for suppressing the shaking of the projection image by hand, and in the case of placement shooting, there is a setting mode for turning off the anti-shake processing, which is described as being selectable on the setting menu screen.

[0003] Japanese Patent Application Laid-Open No. 2008-252480

[0004] In recent years, a handy type of projection device that projects an image onto an arbitrary projection surface such as a wall while being held by hand has been increasingly used. Since such a handy type of projection device can freely change the projection direction by hand, the position of the projection image can be intentionally changed, such as changing the wall serving as the projection surface to another wall. At that time, when the anti-shake correction function for suppressing camera shake (for example, the anti-shake processing of Patent Document 1) is on, the projection image may not smoothly switch to the position to be changed while trying to maintain the position before the change due to the anti-shake correction function.

[0005] An object of the present invention is to provide a portable projection device that can smoothly change the position of a projection image even when having a camera shake function.

[0006] In a portable projection device having an image projection unit that projects a projection image onto a projection surface and a processor, the processor detects a relative change in the position or orientation of the projector with respect to the projection surface as a first relative change, and based on the detection result of the first relative change, performs a projection state maintenance process for suppressing a change in the position, size, or shape of the projection image with respect to the projection surface. The processor detects a relative change in the position of the projection image on the projection surface or the size of the projection image as a second relative change, and when it is determined from the second relative change that the release condition of the projection state maintenance process is satisfied, the projection state maintenance process is released.

[0007] Preferably, the release condition is that the real image projection area onto which the projected image is projected is located in the peripheral part of the projectable area onto which the image projection unit can project the projected image. Preferably, the release condition is that the state in which the real image projection area onto which the projected image is projected is located in the peripheral part of the projectable area onto which the image projection unit can project the projected image is maintained until a specified amount of time has elapsed.

[0008] The image projection unit includes an image projection light source and a projection direction changing unit that changes the projection direction of the projected image illuminated by the image projection light source, and the release condition is preferably when the angle between the projection axis of the projected image and the optical axis of the image projection light source becomes larger than an arbitrary angle. The image projection unit includes an image projection light source and a projection direction changing unit that changes the projection direction of the projected image illuminated by the image projection light source, and the release condition is preferably when the state in which the angle between the projection direction and the optical axis of the image projection light source becomes larger than an arbitrary angle is maintained until an arbitrary time has elapsed. The release condition is preferably when the actual image projection area on which the projected image is projected is no longer included in the projectable area on which the image projection unit can project the projected image.

[0009] The processor preferably notifies that a second relative change corresponding to the release condition has occurred when it is determined that the release condition has been met. The processor preferably notifies by sound, vibration, or movement of the projector. The processor preferably notifies by a change in the outline of the real image projection area on which the projected image is projected. The change in outline preferably indicates the direction in which the position of the projected image changes relatively.

[0010] The system has an imaging unit that captures a projected image on the projection surface, and it is preferable that the processor detects a second relative change based on the captured image obtained by the imaging unit. If the processor determines from the second relative change that the release condition is not met, it is preferable that the projection state maintenance process continues.

[0011] According to the present invention, the position of the projected image can be smoothly changed even when a camera with a hand-shake function is present.

[0012] This is a schematic diagram of a portable projection device. This is an explanatory diagram showing the functions of a portable projection device. This is an explanatory diagram showing the functions performed by the processor in the portable projection device. (A) is an explanatory diagram showing the first relative change, and (B) is an explanatory diagram showing the projection state maintenance process based on the first relative change. (A) is an explanatory diagram showing a trapezoidal projection image, and (B) is an explanatory diagram showing a rectangular projection image corrected by the projection state maintenance process. This is an explanatory diagram showing the second relative change. (A) is an explanatory diagram showing the case where the actual image projection area is located at the periphery of the projectable area, and (B) is an explanatory diagram showing the case where the actual image projection area is no longer included in the projectable area. This is an explanatory diagram showing the image projection light source and projection direction changing unit. This is an explanatory diagram showing that the outline of the actual image projection area flashes. This is an explanatory diagram showing that the flashing of the outline of the actual image projection area indicates the direction in which the position of the projection image changes relatively. (A) is an explanatory diagram showing that the projection state maintenance process is released due to the shaking of the actual image projection area, and (B) is an explanatory diagram showing that the change in the shape of the outline of the actual image projection area indicates the direction in which the position of the projection image changes relatively.

[0013] As shown in Figure 1, the portable projection device 10 projects an image toward the projection surface SC. The portable projection device 10 is equipped with a grip GP that the user holds in their hand, allowing the user to freely change the projection direction of the image. As a result, the portable projection device 10 can project images not only toward a regular projector screen, but also toward a wall or other surface.

[0014] As shown in Figure 2, the portable projection device 10 comprises an image projection unit 12, a processor 13, and an imaging unit 14 within a projector 11 housing. The portable projection device 10 is provided with a program memory (not shown) that stores programs for executing various processes. The processor 13 executes the programs in the program memory to realize the functions of the first detection unit 15, the projection state maintenance processing unit 16, the second detection unit 17, the processing release unit 18, and the notification unit 19, as shown in Figure 3. The image projection unit 12 projects a projection image onto the projection surface SC. The imaging unit 14 is a digital camera or the like, and captures the projection image on the projection surface SC.

[0015] The portable projection device 10 is equipped with a function for suppressing hand shake. To suppress hand shake, the first detection unit 15 detects a relative change in the position or orientation of the projector 11 with respect to the projection surface SC as a first relative change. The projection state maintenance processing unit 16 then performs projection state maintenance processing to suppress changes in the position, size, or shape of the projected image with respect to the projection surface SC, based on the detection result of the first relative change. The first detection unit 15 may also detect a relative change in the position of the projected image PP or the size of the projected image PP with respect to the projection surface SC as a first relative change. In addition to projecting while held in the hand, the portable projection device 10 is also intended to be attached to the chest with a pin or the like and projected onto the palm of the hand. In this case, the projection state maintenance processing suppresses changes in the state of the projected image due to body shake.

[0016] Specifically, as shown in Figure 4(A), if the position relative to the projector 11 changes from position X1 to position X2 due to the user's hand tremor or the like, the first detection unit 15 detects the relative change with respect to an arbitrary position PS on the projection surface SC as the first relative change D1. As shown in Figure 4(B), the projection state maintenance processing unit 16 moves the projected image PP in the direction DX from position X2 to position X1 by an amount of movement equal to the first relative change D1 in order to suppress changes in the position of the projected image PP relative to the projection surface SC. This completes the projection state maintenance process.

[0017] As shown in Figure 5(A), the change in the position of the projector 11 from position X1 to position X2 may cause the shape of the projected image on the projection surface SC to change from a rectangle to a trapezoid with a longer top edge. In this case, as shown in Figure 5(B), the projection state maintenance process can be used to shorten the top edge and return the image to its original rectangular shape. In this case, the projection state maintenance process functions as a trapezoidal correction process, which is commonly found in projectors.

[0018] The portable projection device 10 is equipped with a function for automatically canceling the projection state maintenance process. To cancel the projection state maintenance process, the second detection unit 17 detects a relative change in the position or size of the projected image PP on the projection surface SC as a second relative change. The processing cancellation unit 18 then cancels the projection state maintenance process if it determines from the second relative change that the conditions for canceling the projection state maintenance process are met. On the other hand, if the processing cancellation unit 18 determines from the second relative change that the conditions for cancellation are not met, it continues the projection state maintenance process. The second detection unit 17 may also detect a relative change in the position or orientation of the projector 11 on the projection surface SC as a second relative change. The relative change in the size of the projected image PP also includes changes in scale when moving closer to or further away from the projection surface SC.

[0019] Regarding the detection of the second relative change, as shown in Figure 6, when the position of the center of the projected image PP on the projection plane SC changes from position Y1 to position Y2, the second detection unit 17 detects the change in position relative to an arbitrary position PS on the projection plane SC as the second relative change D2. As a method for detecting the second relative change, for example, the projected image PP on the projection plane SC is captured by the imaging unit 14. In this case, the second detection unit 17 detects the second relative change based on the captured image obtained by the imaging unit 14.

[0020] The conditions for releasing the projection state maintenance process are preferably those that allow the user to intentionally change the position of the projected image. Specifically, as shown in Figure 7(A), the release condition is preferably when the actual image projection area NR on which the projected image PP is projected is located in the peripheral area of ​​the projectable area MR on which the projected image PP can be projected by the image projection unit 12. In this case, the user can easily project the image to another location by releasing the projection state maintenance process, as they are in a situation where they want to project the image to another location.

[0021] Furthermore, considering the case where the actual image projection area is located only briefly in the peripheral area of ​​the projectable area, without the intention of projection elsewhere, the release condition may be set as when the state in which the actual image projection area is located in the peripheral area of ​​the projectable area is maintained for a specified period of time. Also, as shown in Figure 7(B), the release condition may be set as when the actual image projection area is no longer included in the projectable area.

[0022] Furthermore, as shown in Figure 8, if the image projection unit 12 has an image projection light source 12a and a projection direction changing unit 12b that changes the projection direction K of the projected image PP illuminated by the image projection light source 12a, it is preferable that the release condition be when the angle θ between the projection direction K and the optical axis L of the image projection light source 12a becomes larger than an arbitrary angle. The projection direction changing unit 12b is composed of optical members such as lenses and prisms. In this case, since the situation is that the user wants to switch to another projection surface and project the projected image, releasing the projection state maintenance process makes it easier to project the projected image onto the other projection surface. It should also be considered that the user may not intend to project onto another projection surface, but rather fine-tune the position of the projected image on the current projection surface, and the release condition may be when the angle θ between the projection axis Lb of the projected image and the optical axis La becomes larger than an arbitrary angle and this state is maintained for an arbitrary amount of time.

[0023] The notification unit 19, when it determines that the release condition is satisfied, notifies that it is a second relative change corresponding to the release condition. Preferably, the notification unit 19 provides notification by sound, vibration, or movement of the projector 11. Alternatively, the notification unit 19 may provide notification by a change in the outline of the real image projection area on which the projected image is projected.

[0024] Specifically, as shown in Figure 9, the outline NRx of the real image projection area NR is blinked to indicate a second relative change corresponding to the release condition, and that the projection state maintenance process is released. In this case, the hatching of the outline of the real image projection area NR indicates that it is a blinking area. Alternatively, the change in the outline of the real image projection area NR may indicate the direction in which the position of the projected image changes relatively. In this case, as shown in Figure 10, a portion of the outline of the real image projection area NR, NRy, is blinked to indicate that the direction of the blinking portion is the direction in which the position of the projected image changes relatively. The hatching of a portion of the outline of the real image projection area NR indicates that it is a blinking portion, similar to Figure 9.

[0025] Furthermore, as shown in Figure 11(A), the entire real image projection area NR may be made to vibrate slightly to indicate that the projection state maintenance process is being released. In Figure 11(A), the slight vibration is represented by double lines in the upper right and lower left corners of the outline of the real image projection area NR. Also, as shown in Figure 11(B), when the position of the projected image changes relative to direction DY, the shape of the outline of the real image projection area NR in direction DY and its surroundings may be changed to a shape that is pulled in direction DY to indicate that the direction of the relative change in the position of the projected image is direction DY.

[0026] In this embodiment, each process is performed on any computer. Furthermore, any computer may perform these processes using a processor, a program, or a combination thereof. Any computer may be a general-purpose computer, a computer designed for a specific purpose, a workstation, or any other hardware element capable of running a program.

[0027] The processor may consist of one or more hardware components, and the type of hardware is not limited. For example, the processor may consist of programmable logic devices such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), FPGA (Field Programmable Gate Array), dedicated circuits for executing specific processes such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). The processor also has various units or means that execute the various processes in this embodiment. Furthermore, the type of hardware may be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a processor, these components may reside in physically separate devices or in the same device. Furthermore, in any embodiment, the order of the processes performed by the processor is not limited to the order described above and may be changed as appropriate. The hardware components are composed of electrical circuits (circuits) and the like, which are combinations of circuit elements such as semiconductor elements.

[0028] Furthermore, this embodiment may be implemented by hardware, software, firmware, microcode, or a combination thereof. The software, firmware, and microcode are composed of a program. The program may also be, for example, a group of program modules, each of which may be implemented by a processor configured to perform its respective function. The program may be program code or multiple code segments stored on one or more non-temporary computer-readable media (e.g., recording media or other storage). The program may be divided and stored on multiple non-temporary computer-readable media located on devices that are physically separated from each other. The program code or code segment may represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. The program code or code segment may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents.

[0029] 10 Portable projection device 11 Projector 12 Image projection unit 13 Processor 14 Imaging unit 15 First detection unit 16 Projection state maintenance processing unit 17 Second detection unit 18 Processing release unit 19 Notification unit SC Projection surface GP Grip X1, X2 Position PP Projected image D1 First relative change PS Arbitrary position Y1, Y2 Position NR Actual image projection area MR Projectionable area K Projection direction L Optical axis θ Angle DX, DY Direction

Claims

1. A portable projection device having an image projection unit for projecting an image onto a projection surface and a processor, wherein the processor detects a relative change in the position or orientation of the projector with respect to the projection surface as a first relative change, performs a projection state maintenance process to suppress changes in the position, size, or shape of the projected image with respect to the projection surface based on the detection result of the first relative change, detects a relative change in the position or size of the projected image on the projection surface as a second relative change, and releases the projection state maintenance process when it is determined from the second relative change that the conditions for releasing the projection state maintenance process are met.

2. The portable projection device according to claim 1, wherein the release condition is that the actual image projection area on which the projected image is projected is located in the peripheral part of the projectable area on which the projected image can be projected by the image projection unit.

3. The portable projection device according to claim 1, wherein the release condition is that the actual image projection area on which the projected image is projected is located in the peripheral area of ​​the projectable area on which the projected image can be projected by the image projection unit, and this state is maintained until an arbitrary amount of time has elapsed.

4. The portable projection device according to claim 1, wherein the image projection unit comprises an image projection light source and a projection direction changing unit for changing the projection direction of the projected image illuminated by the image projection light source, and the release condition is when the angle between the projection axis of the projected image and the optical axis of the image projection light source becomes greater than an arbitrary angle.

5. The portable projection device according to claim 1, wherein the image projection unit comprises an image projection light source and a projection direction changing unit for changing the projection direction of the projected image illuminated by the image projection light source, and the release condition is maintained for an arbitrary amount of time when the angle between the projection direction and the optical axis of the image projection light source becomes greater than an arbitrary angle.

6. The portable projection device according to claim 1, wherein the release condition is when the actual image projection area on which the projected image is projected is no longer included in the projectable area on which the projected image can be projected by the image projection unit.

7. The portable projection device according to claim 1, wherein the processor, when it is determined that the release condition is satisfied, notifies that the change is the second relative change corresponding to the release condition.

8. The portable projection device according to claim 7, wherein the processor provides notification by sound, vibration, or movement of the projector.

9. The portable projection device according to claim 7, wherein the processor provides notification based on a change in the external shape of the real image projection area on which the projected image is projected.

10. The portable projection device according to claim 9, wherein the change in external shape indicates a direction in which the position of the projected image changes relatively.

11. The portable projection device according to claim 1, comprising an imaging unit for capturing the projected image on the projection surface, wherein the processor detects the second relative change based on the captured image obtained by the imaging unit.

12. The portable projection device according to claim 1, wherein the processor continues the projection state maintenance process when it is determined from the second relative change that the release condition is not met.

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