JP2008089931A - Image display device and method of varying image size - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device which displays an image by two-dimensional scanning of a luminous flux and has at least a small image display mode and a large image display mode and can save electric power, and to provide a method of varying the size of the image. <P>SOLUTION: The image display device displays the image by two-dimensionally scanning the luminous flux, and has at least the small image display mode and the large image display mode, an optical scanning part which two-dimensionally scans the luminous flux and a control part which controls the operation of the optical scanning part, wherein the control part controls the optical scanning part to vary the scanning angle of the luminous flux, thus switches the large image display mode and the small image display mode. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image display device and an image size changing method.

  2. Description of the Related Art Conventionally, an image display apparatus that displays an image by two-dimensionally scanning a light beam generated based on an image signal is known.

  As this type of image display device, a projection-type image display device that projects and displays an image on a screen by two-dimensionally scanning a light beam generated based on the image signal on the screen, or the image signal There is a retinal scanning image display device that scans a light beam generated based on the two-dimensionally and guides it to the user's eyes to form an image on the retina.

In these image display devices, for example, an optical scanning unit that scans a light beam by driving an optical scanning element such as a galvanometer mirror is used, and the reflection surface of the optical scanning element is swung within a predetermined range. In some cases, a light beam corresponding to an image signal is scanned on the reflection surface (see, for example, Patent Document 1).
JP 2004-177477 A

  However, in an image display device using an optical scanning element, an angle for driving the reflection surface of the optical scanning element regardless of the size of an image to be displayed (hereinafter, such an angle is referred to as a “scanning angle”). Was constant.

  Therefore, when only a part of the range that can be scanned by the optical scanning unit is used for scanning the light beam, the power for driving the optical scanning element in the optical scanning unit is wasted.

  Therefore, the present invention displays an image by two-dimensional scanning of a light beam, and can attain power saving in an image display device having at least a small screen display mode and a large screen display mode. The purpose is to provide a resizing method.

  In order to achieve the above object, the invention described in claim 1 is an image display device that displays an image by two-dimensional scanning of a light beam and has at least a small screen display mode and a large screen display mode, An optical scanning unit that two-dimensionally scans the light beam; and a control unit that controls an operation of the optical scanning unit, wherein the control unit controls the optical scanning unit to change a scanning angle of the light beam. Thus, the image display device can be switched between the large screen display mode and the small screen display mode.

  According to a second aspect of the present invention, in the first aspect of the present invention, the control unit controls the optical scanning unit to change the scanning center of the light beam in the small screen display mode. .

  The invention according to claim 3 is the invention according to claim 1 or 2, further comprising a display position change operation unit operated to change a display position of the image, and the control unit changes the display position. The optical scanning unit is controlled to change the scanning center of the light beam on condition that the operating unit is operated.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, further comprising a display mode switching operation unit operated to switch the display mode, wherein the control unit is configured to switch the display mode. The display mode is switched from the small screen display mode to the large screen display mode on condition that the operation unit is operated.

  The invention according to claim 5 is the invention according to any one of claims 1 to 3, wherein the control unit switches to the large screen display mode when a predetermined condition is satisfied in the small screen display mode. It is characterized by.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the optical scanning is performed using an image signal input unit to which an image signal is input and a light beam based on the image signal input to the image signal input unit. A light beam emitting unit that emits light to the image display unit, and the control unit changes the display mode from the small screen display mode to the large screen display mode on condition that the image signal is input to the image signal input unit. It is characterized by switching.

  According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the optical scanning is performed using an image signal input unit to which an image signal is input and a light beam based on the image signal input to the image signal input unit. And the control unit detects the change of the image based on the image signal input to the image signal input unit on the condition that the display mode is changed from the small screen display mode. Switching to the large screen display mode is characterized.

  The invention according to claim 8 is the invention according to any one of claims 5 to 7, further comprising a display mode switching operation unit operated to switch the display mode, wherein the control unit is configured to switch the display mode. The display mode is switched from the large screen display mode to the small screen display mode on condition that the operation unit is operated.

  The invention according to claim 9 is characterized in that, in the invention according to any one of claims 1 to 4, when the predetermined condition is satisfied in the large screen display mode, the mode is switched to the small screen display mode.

  The invention described in claim 10 is the invention described in claim 5, wherein the predetermined condition is that the image to be displayed is a character.

  According to an eleventh aspect of the present invention, in the invention according to the ninth aspect, an image signal input unit to which an image signal is input and a light beam based on the image signal input to the image signal input unit are scanned with the light. When the control unit determines that the image signal is not input to the image signal input unit, the control unit switches the display mode from the large screen display mode to the small screen display mode. It is characterized by that.

  According to a twelfth aspect of the present invention, in the invention according to the ninth aspect, the optical signal is input to the image signal input unit, and the light beam based on the image signal input to the image signal input unit is scanned with the light. The control unit determines that the predetermined condition is satisfied when there is no change in the image based on the image signal input to the image signal input unit, and sets the display mode. The large screen display mode is switched to the small screen display mode.

  A thirteenth aspect of the present invention is the invention according to any one of the ninth to twelfth aspects, further comprising an operation unit operated by a user, and the control unit is provided on the condition that the operation unit is operated. The display mode is switched from the small screen display mode to the large screen display mode.

  The invention according to claim 14 is a screen size changing method in an image display device which displays an image by two-dimensional scanning of a light beam and has at least a small screen display mode and a large screen display mode. An image size changing method for switching between the large screen display mode and the small screen display mode by changing the size of the corner.

  According to the invention described in claims 1 and 14, in the image display device, the size of the image to be displayed is switched by changing the magnitude of the scanning angle of the light beam, so that power saving can be realized by reducing the drive voltage. In addition, it is possible to improve the durability of the scanner by reducing the twist angle.

  According to the second aspect of the present invention, since the scanning center of the light beam is changed by the optical scanning unit, a small screen can be displayed at a desired position.

  According to the third aspect of the present invention, since the scanning center of the light beam is changed by the operation by the user, it is possible to execute display according to the user's request.

  According to the invention described in claim 4, when the user desires, the size of the image to be displayed can be made large.

  According to the fifth aspect of the invention, when the predetermined condition is satisfied in the small screen display mode, the mode is switched to the large screen display mode. Therefore, the small screen is displayed when the predetermined condition is not satisfied. It is possible to reduce power consumption by automatically setting a small screen as a predetermined condition when there is no need to do so.

  According to the sixth aspect of the invention, the display mode is switched from the small screen display mode to the large screen display mode on condition that an image signal is input to the image signal input unit. The user can easily see the contents of the display image.

  According to the seventh aspect of the invention, on the condition that the change of the image based on the image signal input to the image signal input unit is detected, the small screen display mode is switched to the large screen display mode. The user can easily see it.

  According to the invention described in claim 8, since the large screen display mode is switched to the small screen display mode on the condition that the user operates the display mode switching operation unit, the display mode that matches the user's request is selected. Can do.

  According to the ninth aspect of the present invention, the large screen display mode is switched to the small screen display mode when the predetermined condition is satisfied, so that the screen mode can be appropriately selected according to the condition.

  According to the tenth aspect of the present invention, when the image to be displayed is a character, it is displayed on a small screen, so that power saving can be achieved.

  According to the eleventh aspect of the invention, when it is determined that no image signal is input to the image signal input unit, the large-screen display mode is switched to the small-screen display mode. Power saving can be achieved by displaying information indicating that there is no signal on a small screen.

  According to the twelfth aspect of the present invention, when there is no change in the image based on the input image signal, the large screen display mode is switched to the small screen display mode. Power saving can be achieved by displaying on a large screen only in cases.

  According to the thirteenth aspect of the invention, since the small screen display mode is switched to the large screen display mode on the condition that the operation unit is operated, the large screen display mode can be changed according to the user's request. .

  Hereinafter, an embodiment of an image display device according to the present invention will be described with reference to the drawings. In this embodiment, the image display device is an image display device that is used on the user's head as the image display device. The light beam generated based on the image signal is scanned two-dimensionally and scanned. A retinal scanning type head mounted display (hereinafter referred to as “HMD: Head Mount Display”) that guides light to the eye and forms an image on the retina will be described as an example, but the present invention is limited to this. The present invention is also applicable to a projection-type image display device such as a laser projector that projects an image on a screen by two-dimensionally scanning a light beam generated based on an image signal on the screen. It is something that can be done.

  FIG. 1 is an explanatory diagram illustrating an example of a state in which an image display mode is switched by the image display apparatus according to the present embodiment, and FIG. 2 is a functional block illustrating an electrical configuration of the image display apparatus according to the present embodiment. FIG.

(Overview of display mode switching by image display device)
The HMD which is the image display device of the present embodiment is a device for viewing an image such as video content while being worn on the head of the user, and a light beam obtained by modulating the image signal is applied to at least one retina of the user. Projecting and two-dimensionally scanning to display an image (projection display) has at least a small screen display mode and a large screen display mode.

  Here, the large screen display mode is a mode in which, when the HMD is normally used, the size of the image to be displayed is set to a predetermined maximum size that the user feels easy to see. Is a mode in which the size of an image to be displayed is set smaller than that in the large screen display mode.

  The HMD has an optical scanning unit that two-dimensionally scans the light beam and a control unit that controls the operation of the optical scanning unit. The control unit controls the scanning angle of the light beam to the optical scanning unit. By changing, the large screen display mode and the small screen display mode are switched.

  That is, in the large screen display mode, as shown in FIG. 1A, the control unit displays a large screen image V1 by two-dimensionally scanning a light beam with a relatively large scanning angle. In addition, when the large screen display mode is changed to the small screen display mode, the control unit reduces the light beam scanning range by reducing the light beam scanning angle as compared with the large screen display mode. An image V2 with a smaller image area than that in the display mode is displayed.

  Here, in the present embodiment, the change of the light beam scanning range is performed by controlling a horizontal scanning unit which is a first optical scanning unit and a vertical scanning unit which is a second optical scanning unit, which will be described later. The horizontal scanning unit has a function of scanning the image in the horizontal direction, and the vertical scanning unit has a function of scanning the image in the vertical direction.

  In the small screen display mode, as shown in FIG. 1B, in addition to the vertical direction, the image V2 is obtained by reducing the horizontal scanning range, and as shown in FIG. 1C, only the vertical scanning range is reduced. There is an image V3.

  The vertical scanning range is reduced by reducing the scanning angle of the light beam by the vertical scanning unit. The horizontal scanning range is reduced by reducing the scanning angle of the light beam by the horizontal scanning unit.

  As described above, the HMD of this embodiment is configured to switch from the large screen display mode to the small screen display mode by reducing the scanning angle of the light beam by the optical scanning unit. This can reduce the power consumption of the HMD.

  Also, in the case of using an optical scanning element such as a galvano mirror that supports a reflecting surface that reflects a light beam with an elastic beam and shakes the reflecting surface by driving the elastic beam in the optical scanning unit. Since the twist angle of the optical scanning element is reduced as the scanning angle of the light beam (the swing width of the reflecting surface) is reduced, the durability of the optical scanning element can be improved.

  By the way, the switching between the large screen display mode and the small screen display mode can be performed by the user of the HMD operating a display mode switching operation unit described later, and the small screen display mode can be switched from the large screen display mode to the small screen under a predetermined condition. Switching to the screen display mode or switching from the small screen display mode to the large screen display mode is enabled.

  For example, when there is no input of an image signal to the HMD or when there is no change in the image signal input to the HMD, the scanning angle of the light beam scanned by the optical scanning element is reduced, thereby reducing the large screen display mode. Switch to screen display mode. On the other hand, when the image signal is input to the HMD or when the image signal input to the HMD is changed, the small-screen display mode is increased by increasing the scanning angle of the light beam scanned by the optical scanning element. Switch to screen display mode.

  Furthermore, in the present embodiment, the control unit changes the image display position by changing the scanning center of the light beam in the optical scanning unit in the small screen display mode. Here, the scanning center means the center of the scanning range of the luminous flux by the optical scanning unit, and the scanning range of the luminous flux by the optical scanning unit is symmetric with respect to this scanning center.

  That is, the scanning center of the light beam can be changed by the HMD user operating a display position changing operation unit described later in the small screen display mode.

  The change of the scanning center of the light beam by the optical scanning unit is performed by changing the center of the deflection angle of the reflection surface of the optical scanning element. However, the entire optical scanning element is inclined by a driving means such as a motor. May be.

  For example, as shown in FIGS. 1C and 1D, the scanning center C in the vertical direction of the light beam in the image V3 is changed to a scanning center C ′ positioned above the scanning center C in the vertical direction. As a result, the image V3 ′ in which the display position of the image V3 is changed is displayed.

  As described above, the HMD of the present embodiment is configured to change the display position of the image by changing the scanning center of the light beam. Therefore, the display position of the image is changed to a position desired by the user. It is possible to realize an image display that is rich in change and highly interesting.

  Hereinafter, the configuration and operation of the HMD in the present embodiment will be specifically described.

(Description of electrical configuration of image display device)
Next, the electrical configuration and the like of the HMD 1 of the present embodiment will be described with reference to FIG.

  As shown in FIG. 2, the HMD 1 reads out an image signal supplied from an external apparatus for each dot clock, and intensity-modulated in accordance with the read image signal. A light beam generation unit 20 that generates and emits a light beam is provided, and is further generated between the light beam generation unit 20 and the user's eye E by the light beam generation unit 20 and is emitted through the optical fiber 100. A collimating optical system 61 that collimates a laser beam (hereinafter referred to as “light beam”), and a light beam collimated by the collimating optical system 61 reciprocates in the horizontal direction (primary direction) for image display. A horizontal scanning unit 70 that functions as a first optical scanning unit that scans, and a second optical scanning unit that reciprocally scans a light beam scanned in the horizontal direction by the horizontal scanning unit 70 in a vertical direction (secondary direction different from the primary direction) Function as The vertical scanning unit 80, the relay optical system 75 provided between the horizontal scanning unit 70 and the vertical scanning unit 80, and the light beam thus scanned in the horizontal and vertical directions are emitted to the pupil Ea. A relay optical system 90 is provided.

  In the present embodiment, the horizontal scanning unit 70, the relay optical system 75, the vertical scanning unit 80, and the relay optical system 90 scan the light beam generated based on the image signal in a two-dimensional manner. This corresponds to the optical scanning unit to be displayed.

  Further, the light beam generation unit 20 has a function as an image signal input unit to which an image signal supplied from an external device is input, and each element serving as an element for synthesizing an image based on the input image signal. An image signal processing unit 21 that generates a signal or the like is provided. In the image signal processing unit 21, blue (B), green (G), and red (R) image signals 22a to 22c are generated and output. Is done. Further, the image signal processing unit 21 outputs a horizontal synchronization signal 23 used in the horizontal scanning unit 70 and a vertical synchronization signal 24 used in the vertical scanning unit 80, respectively.

  Further, the light beam generation unit 20 includes a light source unit 30 that converts the three image signals (B, R, G) 22a to 22c output for each dot clock from the image signal processing unit 21 into light beams, and these three light beams. Is combined with a single light beam to generate an arbitrary light beam.

  The light source unit 30 includes a B laser 34 that generates a blue light beam and a B laser driver 31 that drives the B laser 34, a G laser 35 that generates a green light beam, a G laser driver 32 that drives the G laser 35, and a red color. And an R laser driver 33 for driving the R laser 36. Each of the lasers 34, 35, and 36 can be configured as, for example, a semiconductor laser or a solid-state laser with a harmonic generation mechanism. When a semiconductor laser is used, the drive current can be directly modulated to modulate the intensity of the light beam. However, when a solid-state laser is used, each laser is equipped with an external modulator to modulate the intensity of the light beam. There is a need.

  The light combining unit 40 includes collimating optical systems 41, 42, and 43 provided to collimate a light beam incident from the light source unit 30 into parallel light, and dichroic mirrors 44, 45, and 46 for combining the collimated light beam. And a coupling optical system 47 that guides the combined light flux to the optical fiber 100.

  Laser beams emitted from the lasers 34, 35, and 36 are collimated by collimating optical systems 41, 42, and 43, and then enter the dichroic mirrors 44, 45, and 46. Thereafter, these dichroic mirrors 44, 45, and 46 selectively reflect and transmit each light beam with respect to the wavelength.

  Specifically, the blue light beam emitted from the B laser 34 is collimated by the collimating optical system 41 and then enters the dichroic mirror 44. The green light beam emitted from the G laser 35 enters the dichroic mirror 45 through the collimating optical system 42. The red light beam emitted from the R laser 36 enters the dichroic mirror 46 through the collimating optical system 43.

  The light beams of the three primary colors respectively incident on the three dichroic mirrors 44, 45 and 46 selectively reflect or transmit the wavelength, reach the coupling optical system 47, and are collected and output to the optical fiber 100.

  The horizontal scanning unit 70 and the vertical scanning unit 80 scan in the horizontal direction and the vertical direction to form a scanning light beam so that the light beam incident from the optical fiber 100 can be projected as an image. At this time, the light beam generation unit 20, the optical fiber 100, and the collimating optical system 61 function as a light beam emission unit that emits a light beam based on the image signal input to the image signal input unit to the optical scanning unit.

  The horizontal scanning unit 70 resonates the optical scanning element 71 having a reflection surface to scan the light beam in the horizontal direction and swings the reflection surface of the optical scanning element 71, in other words, optical scanning. A horizontal scanning drive circuit 72 as a drive signal generator for generating a drive signal for resonantly driving the element 71; The horizontal scanning unit 70 is designed to scan the light beam at a higher speed, that is, at a higher frequency than the vertical scanning unit 80.

  The vertical scanning unit 80 includes an optical scanning element 81 for scanning the light beam in the vertical direction, and a vertical scanning control circuit 82 for driving the optical scanning element 81.

  The optical scanning element 71 of the horizontal scanning unit 70 and the optical scanning element 81 of the vertical scanning unit 80 are resonantly driven as described above as long as their reflection surfaces are swung so as to scan light. However, the driving method may be any driving method such as piezoelectric driving, electromagnetic driving, or electrostatic driving.

  Further, the horizontal scanning driving circuit 72 and the vertical scanning control circuit 82 are driven based on the horizontal synchronizing signal 23 and the vertical synchronizing signal 24 output from the image signal processing unit 21, respectively.

  The control unit 110 described in detail later adjusts the horizontal synchronization signal 23 and the vertical synchronization signal 24 by controlling the operation of the image signal processing unit 21 to thereby adjust the horizontal scanning unit 70 and the vertical scanning unit 80. For example, as shown in FIG. 1B, the size of the image to be displayed is changed by changing the scanning angle of the luminous flux.

  In the case of resonance driving in the present embodiment, at least the vertical scanning unit 80 of the horizontal scanning unit 70 and the vertical scanning unit 80 changes the scanning angle of the light beam so as to change the size of the image to be displayed. good. The reason why at least the vertical scanning unit 80 changes the scanning angle of the light beam is that, in the case of resonance driving, the scanning in the vertical direction is slower and easier to control than the scanning in the horizontal direction. This is because it is particularly effective when the size of the image to be displayed is changed only in the vertical direction, as shown in c).

  The control unit 110 also controls the operation of the image signal processing unit 21 to adjust the horizontal synchronization signal 23 and the vertical synchronization signal 24 to thereby cause the horizontal scanning unit 70 and the vertical scanning unit 80 to scan the light beam. To change. Specifically, the control unit 110 controls the drive voltage of a driving unit such as a motor (not shown) provided in each of the horizontal scanning unit 70 and the vertical scanning unit 80 so that the scanning center is shifted, and drives the driving unit. By doing so, the optical scanning element 71 and the optical scanning element 81 themselves are inclined to change the scanning center of the light beam. Thus, if the drive voltage is controlled so that the scanning center is shifted, the display position of the image can be changed as shown in FIG. 1D, for example.

  In addition, a relay optical system 75 that relays a light beam between the horizontal scanning unit 70 and the vertical scanning unit 80 is provided, and the light scanned in the horizontal direction by the optical scanning element 71 passes through the relay optical system 75. Then, it is scanned in the vertical direction by the optical scanning element 81 and emitted to the relay optical system 90 as a scanning light beam.

  The relay optical system 90 includes lens systems 91 and 94 having a positive refractive power. The display scanning light beams emitted from the vertical scanning unit 80 are converted into convergent light beams by the lens system 91 so that the respective light beams have their center lines parallel to each other. The lens system 94 converts the light beams into substantially parallel light fluxes, and the center line of these light fluxes is converged on the pupil Ea of the user.

  In this embodiment, the light beam incident from the optical fiber 100 is scanned in the horizontal direction by the horizontal scanning unit 70 and then scanned in the vertical direction by the vertical scanning unit 80. The arrangement with the vertical scanning unit 80 may be exchanged, and after the vertical scanning unit 80 scans in the vertical direction, the horizontal scanning unit 70 may scan in the horizontal direction.

  The control unit 110 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, and a RAM (Random Access Memory) 103.

  The CPU 101, the ROM 102, and the RAM 103 are connected to a data communication bus, and various information is transmitted and received through the data communication bus.

  Moreover, this control part 110 is connected with the operation part 6 operated by the user. The operation unit 6 is provided with a plurality of switches (not shown) operated by the user.

  Specifically, although illustration is omitted, an image change function selection switch for selecting an image change function for changing the size of an image displayed on the HMD 1 and a display position change operated for changing the display position of the image A display position change switch as an operation unit, a display mode changeover switch as a display mode switching operation unit operated to switch between a small screen display mode and a large screen display mode are provided.

  The CPU 101 is an arithmetic processing unit that operates various circuits (not shown) constituting the HMD 1 by executing various programs stored in the ROM 102 and executes various functions provided in the HMD 1.

  The ROM 102 is an image reproduction program for operating the light beam generation unit 20, the horizontal scanning unit 70, the vertical scanning unit 80, and the like when an image is reproduced, stopped, fast-forwarded, rewound, etc. by the HMD 1. The control unit 110 is executed by the CPU 101 to control the entire operation of the HMD 1 such as a screen change function program for operating the optical scanning unit such as the horizontal scanning unit 70 and the vertical scanning unit 80 when changing the size. It functions as a program storage means for storing various programs.

  The RAM 103 is temporary storage means that is used as a work area when the CPU 101 executes various programs stored in the ROM 102 and stores various flags.

  The RAM 103 temporarily stores image information corresponding to video content input as an image signal from an external device via an interface unit (not shown), and when displaying an image by the HMD 1. The control unit 110 reads the image information temporarily stored in the RAM 103 and performs a process of displaying an image.

  As described above, the control unit 110 of the HMD 1 configured as described above scans the light beam at at least one of the horizontal scanning unit 70 that is the first scanning unit and the vertical scanning unit 80 that is the second optical scanning unit. The size of the image to be displayed is changed by performing control to change the image.

  That is, when the screen change function selection switch provided in the operation unit 6 is operated to change the size of the image displayed by the user, the control unit 110 loads the screen change function program stored in the ROM 102. The control is performed so that the light scanning element 71 and the light scanning element 81 of the light scanning unit change the scanning angle of the light beam according to the operation of the display mode changeover switch.

(Description of processing performed by control unit of image display device)
Next, processing performed by the control unit 110 in the HMD 1 of the present embodiment will be described with reference to FIGS. 3 is a flowchart showing a main process performed by the control unit 110 of the HMD 1 according to the present embodiment, FIG. 4 is a flowchart showing a screen change function process performed by the control unit 110 of the HMD 1 according to the present embodiment, and FIG. FIG. 6 is a flowchart showing a second scanning angle changing process performed by the control unit 110 of the HMD 1 according to the present embodiment.

(Description of main processing)
As shown in FIG. 3, in the main process, when the power is turned on, the control unit 110 first performs an initial setting process such as permitting access to a hard disk (not shown) and initializing the work area of the RAM 103 (step S1) and the process proceeds to step S2.

  In step S2, control unit 110 determines whether a screen change function has been selected. Specifically, it is determined whether or not the screen change function has been selected based on whether or not a signal indicating that the screen change function selection switch provided on the operation unit 6 has been pressed by the user has been received. .

  In this process, when the control unit 110 determines that the screen change function is not selected (step S2: No), the process proceeds to step S3, and when it is determined that the screen change function is selected (step S2: Yes), The process moves to step S5.

  In step S3, the control unit 110 performs control to set the scanning angle of the light beam scanned by the optical scanning unit to a large value, and moves the process to step S4. Specifically, the control unit 110 controls the large display mode by controlling the light beam to scan at least one of the horizontal scanning unit 70 and the vertical scanning unit 80 at a scanning angle corresponding to the large screen display mode. The screen display mode is set.

  In step S5, the control part 110 performs a screen change function process, and moves a process to step S4. This screen change function process is a process of steps S10 to S16 in FIG. 4 and will be described in detail later.

  In step S4, the control unit 110 determines whether or not the power of the HMD 1 has been turned off.

  If it is determined in this process that the power is turned off (step S4: Yes), the control unit 110 stops the operation of the HMD 1 and ends the main process.

On the other hand, if it is determined in this process that the power is not turned off (step S4: No), the control unit 110 shifts the process to step S2 and repeats the process from step S2.
(Description of screen change function processing)
Next, the screen change function process performed by the control unit 110 in step S5 of the main process will be described with reference to FIG.

  In this screen change function process, the control unit 110 first determines whether there is an input of an image signal from the external device to the HMD 1 (step S10).

  If it is determined in step S10 that there is no image signal input (step S10: Yes), the control unit 110 moves the process to step S11, sets a no-signal flag, and a value indicating that no image signal is input to the HMD1. After being set to “1”, the process proceeds to step S12.

  In step S <b> 11, the control unit 110 sets the no signal flag to “1”, and creates image information indicating that there is no input signal such as “No Signal” and stores the image information in the RAM 103.

  In step S12, the control unit 110 performs control to set the scanning angle of the light beam scanned by the optical scanning unit to be small, and moves the process to step S13. Specifically, the control unit 110 controls the display mode to be reduced by performing control to scan the light beam at a scanning angle corresponding to the small screen display mode on at least one of the horizontal scanning unit 70 and the vertical scanning unit 80. The screen display mode is set.

  In step S13, the control unit 110 performs the first scanning angle changing process, ends the screen changing function process, and returns the process to the main process. This first scanning angle changing process is a process in which the control unit 110 determines whether or not a predetermined condition is satisfied, and when the predetermined condition is satisfied, the display mode changed to the small screen display mode in step S12 is switched to the large screen display mode. is there. The first scanning angle changing process will be specifically described later with reference to FIG.

  On the other hand, if it is determined in step S10 that there is an input of an image signal (step S10: No), the control unit 110 moves the process to step S14 and determines whether or not the default is the small screen mode.

  Here, the control unit 110 determines whether or not the default is the small screen display mode by determining whether or not the small screen display mode is set as the default value stored in the RAM 103 in advance. is there. Note that the default value stored in advance in the RAM 103 can be changed to the large screen display mode by the user's setting.

  In step S14, when the control unit 110 determines that the default is the small screen display mode (step S14: Yes), the control unit 110 proceeds to step S12 and determines that the default is not the small screen display mode (step S14: No). Then, the process proceeds to step S15.

  In step S15, the control unit 110 performs control to set the scanning angle of the light beam scanned by the optical scanning unit to a large value, and the process proceeds to step S16. Specifically, the control unit 110 controls the large display mode by controlling the light beam to scan at least one of the horizontal scanning unit 70 and the vertical scanning unit 80 at a scanning angle corresponding to the large screen display mode. The screen display mode is set.

In step S16, the control unit 110 performs the second scanning angle change process, ends the screen change function process, and returns the process to the main process. This second scanning angle changing process is a process in which the control unit 110 determines whether or not a predetermined condition is satisfied, and when the predetermined condition is satisfied, the display mode set to the large screen display mode in step S15 is switched to the small screen display mode. is there. The second scanning angle changing process will be specifically described later with reference to FIG.
(Description of first scanning angle changing process)
Next, the first scanning angle changing process performed by the control unit 110 in step S13 of the screen changing function process will be described with reference to FIG.

  In the first scanning angle changing process, the control unit 110 first determines whether or not the display mode changeover switch of the operation unit 6 has been pressed (step S20).

  In step S20, when the control unit 110 determines that the display mode switch of the operation unit 6 has been pressed (step S20: Yes), the process proceeds to step S21, and the display mode switch of the operation unit 6 is pressed. If it is determined that it is not (step S20: No), the process proceeds to step S22.

  In step S21, the control unit 110 performs control to change the scanning angle of the light beam scanned by the optical scanning unit from small to large, ends the first scanning angle changing process, and returns the process to the image changing function process. Specifically, the control unit 110 controls the display mode to be reduced by performing a control of scanning a light beam at a scanning angle corresponding to the large screen display mode on at least one of the horizontal scanning unit 70 and the vertical scanning unit 80. The screen display mode is switched to the large screen display mode.

  In step S22, the control unit 110 determines whether or not the no-signal flag is “1”. If the no-signal flag is not “1” (step S22: No), the process proceeds to step S25. If the no-signal flag is “1” (step S22: Yes), the process proceeds to step S23.

  In step S23, the control unit 110 determines whether or not there is an input of an image signal from the external device to the HMD 1, and when it is determined that there is an input of an image signal (step S23: Yes), the control unit 110. Moves the process to step S24, sets the no-signal flag to “0”, which is a value indicating that the image signal is input to the HMD1, and then moves the process to step S21, where no image signal is input. (Step S23: No), the process is moved to step S25.

  In step S25, the control unit 110 determines whether or not the still flag is “1”, which is a value indicating that there is no change in the image based on the image signal input to the HMD1, and the still flag is “1”. If not (step S25: No), the first scanning angle changing process is terminated and the process is returned to the image changing function process. If the still flag is “1” (step S25: Yes), step S26 is performed. Move processing to.

In step S26, the control unit 110 determines whether or not there is a change in the image based on the image signal input from the external device to the HMD 1, and when there is a change in the image based on the image signal (step S26: Yes). ), The process proceeds to step S27, the still flag is set to “0”, which is a value indicating that there is a change in the image based on the image signal input from the external device to the HMD 1, and the process proceeds to step S21. When there is no change in the image based on the image signal (step S26: No), the first scanning angle changing process is terminated and the process is returned to the image changing function process.
(Description of second scanning angle changing process)
Next, the second scanning angle changing process performed by the control unit 110 in step S16 of the screen changing function process will be described with reference to FIG.

  In the second scanning angle changing process, the control unit 110 first determines whether or not the display mode changeover switch of the operation unit 6 has been pressed (step S30).

  In step S30, when the control unit 110 determines that the display mode switch of the operation unit 6 has been pressed (step S30: Yes), the process proceeds to step S31, and the display mode switch of the operation unit 6 is pressed. If it is determined that it is not present (step S30: No), the process proceeds to step S32.

  In step S31, the control unit 110 performs control to change the scanning angle of the light beam scanned by the optical scanning unit from large to small, ends the second scanning angle changing process, and returns the process to the image changing function process. Specifically, the control unit 110 increases the display mode by performing control to scan at least one of the horizontal scanning unit 70 and the vertical scanning unit 80 with a scanning angle corresponding to the small screen display mode. The screen display mode is switched to the small screen display mode.

  In step S31, the control unit 110 reads out image information created in step S11 from the RAM 103, such as “No Signal” indicating that there is no input signal, and performs image signal processing on an image based on this image information. The unit 21 is controlled and displayed.

  Further, in step S31, when the control unit 110 determines that the display position change switch has been pressed, the control unit 110 performs control to change the scanning center of the light beam scanned by the optical scanning unit, thereby changing the display position of the screen. It is supposed to be.

  In step S32, the control unit 110 determines whether or not the no-signal flag is “0”. If the no-signal flag is not “0” (step S32: No), the process proceeds to step S35. If the no-signal flag is “0” (step S32: Yes), the process proceeds to step S33.

  In step S33, the control unit 110 determines whether there is an input of an image signal from the external device to the HMD 1, and when determining that there is no input of an image signal (step S33: Yes), the control unit 110. Moves the process to step S34, sets the no signal flag to “1”, which is a value indicating that no image signal is input to the HMD1, and then moves the process to step S31 to input an image signal. (Step S33: No), the process is moved to step S35.

  In step S35, the control unit 110 determines whether or not the still flag is “0”, which is a value indicating that there is a change in the image based on the image signal input to the HMD1, and the still flag is “0”. If not (step S35: No), the second scanning angle changing process is terminated and the process is returned to the image changing function process. If the still flag is "0" (step S35: Yes), step S36 is executed. Move processing to.

  In step S36, the control unit 110 determines whether or not there is an image change based on the image signal input from the external device to the HMD 1, and when there is no image change based on the image signal (step S36: Yes). ), The process proceeds to step S37, the still flag is set to “1” which is a value indicating that there is no change in the image based on the image signal input from the external device to the HMD1, and the process proceeds to step S31. If there is an image change based on the image signal (step S36: No), the second scanning angle changing process is terminated and the process returns to the image changing function process.

  In the above, switching between the large screen display mode and the small screen display mode is performed according to the operation of the display mode switch, whether or not an image signal is input, and whether or not there is a change in the image based on the image signal. Can be switched. For example, when the input image signal can include character information and image information as content, switching between the large screen display mode and the small screen display mode is performed according to the character information and the image information as follows. It can be performed.

  That is, when only the character information is included in the image signal, an image based on the character information is displayed in the small screen display mode, and when the image signal is included in the image signal, the large screen display is performed. An image based on the image signal is displayed depending on the mode.

  Here, the image signal that can include character information and image information refers to an image signal in which a character information signal is inserted during a blanking period of the image information signal, for example, in the case of an analog signal, In the case of a digital signal, for example, it is an image signal in which character information and image information are distinguished by adding a header or the like.

  Hereinafter, this process will be specifically described with reference to the drawings. FIG. 7 is a flowchart showing an example of scanning angle changing processing based on an image signal that can include character information in addition to image information, and FIG. 8 is a diagram showing a display example in this processing.

  As shown in FIG. 7, when an image signal containing only character information is input to the HSD 1, the control unit 110 controls the horizontal scanning unit 70 and the vertical scanning unit 80 to display the display mode in a small screen. The mode (the size of the image displayed at this time is shown in FIGS. 1B to 1D), and an image based on the input image signal is displayed (step S41). An example of the image displayed at this time is shown in FIG.

  Thereafter, the control unit 110 determines whether an image signal including content that cannot be displayed in the small screen display mode has been input (step S42). This determination is made based on whether image information is included in the input image signal. That is, when image information is included in the image signal, it is determined that content that cannot be displayed in the small screen display mode is included.

  In step S42, when it is determined that the content that cannot be displayed in the small screen display mode is not included (step S42: No), the control unit 110 moves the process to step S45 and displays the content in the small screen display mode. If it is determined that content that cannot be performed is included (step S42: Yes), the process proceeds to step S43.

  In step S43, the control unit 110 controls the horizontal scanning unit 70 and the vertical scanning unit 80 to increase the scanning angle to change the display mode to the large screen display mode (the size of the image displayed at this time is shown in FIG. Refer to a)), and the process proceeds to step S44.

  In step S44, the control unit 110 displays an image based on the input image signal, and the process proceeds to step S45. An example of the image displayed at this time is shown in FIG.

  In step S45, the control unit 110 determines whether an image signal including content that does not need to be displayed in the large screen display mode is input. This determination is made based on whether only the character information is included in the input image signal. That is, when only the character information is included in the image signal, it is determined that the content that does not need to be displayed in the large screen display mode is included.

  In this process, when the control unit 110 determines that content that does not need to be displayed in the large screen display mode is not included (step S45: No), the control unit 110 moves the process to step S42 and displays the content in the large screen display mode. If it is determined that content that does not need to be included is included (step S45: Yes), the process proceeds to step S46.

  In step S46, the control unit 110 controls the horizontal scanning unit 70 and the vertical scanning unit 80 to reduce the scanning angle and change the display mode to the small screen display mode (the size of the image displayed at this time is shown in FIG. b) to FIG. 1 (d)), and the process proceeds to step S47.

  In step S47, the control unit 110 displays an image based on the input image signal. Thereafter, the control unit 110 repeatedly performs the process of step S42.

  Here, the image information has been described as an example of content that cannot be displayed in the small screen display mode. However, when the size of the image to be displayed based on the image information is small, the small screen display mode is used. You may make it display. That is, the small screen display mode and the large screen display mode are switched according to the size of the image based on the image signal.

  Here, the large screen display mode and the small screen display mode are switched according to the content included in the input image signal. However, the large screen display mode and the small screen display mode are switched. By doing so, the display mode of the image to be displayed based on the content may be changed.

  For example, a case where an image signal including only character information is input to the HSD 1 will be described with reference to FIG. As shown in FIG. 9A, in the large screen display mode, the display mode is displayed on the large screen when an image signal including only text information consisting of “A ...” is input as content. When the mode is switched to the small screen display mode, the image display mode is changed to the display mode shown in FIG.

  At this time, the control unit 110 controls the horizontal scanning unit 70 to reduce the horizontal scanning range, set the display mode to the small screen display mode, and control the image signal processing unit 21 to convert the character information into character information. The number of characters displayed per line is changed from 7 characters shown in FIG. 9A to 3 characters shown in FIG. 9B and displayed.

  As described above, in the HMD 1 in the present embodiment, the size of the image to be displayed is changed by changing the magnitude of the scanning angle of the light beam, so that power saving can be realized by reducing the drive voltage. In addition, the durability of the scanner can be improved by reducing the twist angle.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims.・ Change is possible.

It is explanatory drawing which shows an example of the state which switched the display mode of the image by the image display apparatus which concerns on this embodiment. It is a functional block diagram which shows the electric constitution of the image display apparatus which concerns on this embodiment. It is a flowchart which shows the main process which the control part of the image display apparatus which concerns on this embodiment performs. It is a flowchart which shows the screen change function process which the control part of the image display apparatus which concerns on this embodiment performs. It is a flowchart which shows the 1st scanning angle change process which the control part of the image display apparatus which concerns on this embodiment performs. It is a flowchart which shows the 2nd scanning angle change process which the control part of the image display apparatus which concerns on this embodiment performs. It is a flowchart which shows the example of the scanning angle change process based on the image signal which can contain character information in addition to image information. It is a figure which shows the example of a display in the scanning angle change process shown in FIG. It is a figure for demonstrating the aspect which the display mode of the image changed when the image signal containing only character information is input into the image display apparatus.

Explanation of symbols

1 HMD (image display device)
6 Operation part V1-V3, V3 'Image 110 Control part 20 Light flux generation part 70 Horizontal scanning part 71 Optical scanning element 75 Relay optical system 80 Vertical scanning part 81 Optical scanning element 90 Relay optical system

Claims (14)

An image display device that displays an image by two-dimensional scanning of a light beam and has at least a small screen display mode and a large screen display mode,
An optical scanning unit for two-dimensionally scanning the luminous flux;
A control unit for controlling the operation of the optical scanning unit,
The said control part is an image display apparatus which switches the said large screen display mode and the said small screen display mode by performing control which changes the scanning angle of the said light beam to the said optical scanning part.   The image display apparatus according to claim 1, wherein the control unit controls the optical scanning unit to change a scanning center of the light beam in the small screen display mode. A display position change operation unit operated to change the display position of the image;
3. The control unit according to claim 1, wherein the control unit controls the optical scanning unit to change a scanning center of the light beam on condition that the display position changing operation unit is operated. Image display device. A display mode switching operation unit that operates to switch the display mode;
The control unit switches the display mode from the small screen display mode to the large screen display mode on condition that the display mode switching operation unit is operated. The image display device according to item 1.   4. The image display device according to claim 1, wherein the control unit switches to the large screen display mode when a predetermined condition is satisfied in the small screen display mode. 5. An image signal input unit to which an image signal is input;
A light beam emitting unit that emits a light beam based on the image signal input to the image signal input unit to the optical scanning unit;
6. The control unit according to claim 5, wherein the control unit switches the display mode from the small screen display mode to the large screen display mode on condition that the image signal is input to the image signal input unit. Image display device. An image signal input unit to which an image signal is input;
A light beam emitting unit that emits a light beam based on the image signal input to the image signal input unit to the optical scanning unit;
The control unit switches the display mode from the small screen display mode to the large screen display mode on condition that an image change based on an image signal input to the image signal input unit is detected. The image display apparatus according to claim 5. A display mode switching operation unit that operates to switch the display mode;
8. The control unit according to claim 5, wherein the control unit switches the display mode from the large screen display mode to the small screen display mode on condition that the display mode switching operation unit is operated. The image display device according to item 1.   5. The image display device according to claim 1, wherein the control unit switches to the small screen display mode when a predetermined condition is satisfied in the large screen display mode. 6.   The image display apparatus according to claim 9, wherein the predetermined condition is that the image to be displayed is a character. An image signal input unit to which an image signal is input;
A light beam emitting unit that emits a light beam based on the image signal input to the image signal input unit to the optical scanning unit;
The said control part switches the said display mode from the said large screen display mode to the said small screen display mode, when it determines with the said image signal input not being input to the said image signal input part. Image display device. An image signal input unit to which the image signal is input;
A light beam emitting unit that emits a light beam based on the image signal input to the image signal input unit to the optical scanning unit,
The control unit determines that the predetermined condition is satisfied when there is no change in the image based on the image signal input to the image signal input unit, and changes the display mode from the large screen display mode to the small screen display mode. The image display device according to claim 9, wherein the image display device is switched to. An operation unit operated by the user is provided.
13. The control unit according to claim 9, wherein the control unit switches the display mode from the small screen display mode to the large screen display mode on condition that the operation unit is operated. The image display device described. A screen size changing method in an image display device that displays an image by two-dimensional scanning of a light beam and has at least a small screen display mode and a large screen display mode,
An image size changing method for switching between the large screen display mode and the small screen display mode by changing the magnitude of the scanning angle of the light beam.

Images