WO2010095347A1

WO2010095347A1 - Head mounted display

Info

Publication number: WO2010095347A1
Application number: PCT/JP2010/000181
Authority: WO
Inventors: 矢田裕紀
Original assignee: ブラザー工業株式会社
Priority date: 2009-02-20
Filing date: 2010-01-14
Publication date: 2010-08-26
Also published as: JP2010191303A

Abstract

Disclosed is a head mounted display through which a user can view a content image represented by content data and which comprises an image presentation means, a judging means, and an image presentation control means. The image presentation means emits light for each unit of pixels which form the content image to output image light which represents a partial image contained in the content image. The judging means judges whether the partial image is a line-drawn image which is represented by a line drawing or is a non line-drawn image which is represented by a drawing other than the line drawing. If the judging means judges that the partial image is a line-drawn image, the image presentation control means controls the image presentation means to emit image light which represents the line-drawn image at an output value corresponding to a first emission output value. If the judging means judges that the partial image is a non line-drawn image, the image presentation control means controls the image presentation means to emit image light which represents the non-line drawn image at an output value corresponding to a second emission output value lower than the first emission output value.

Description

Head mounted display

The present disclosure relates to a head-mounted display that presents a content image indicated by content data to a user's eyes so that the user can recognize the content image.

A technology related to a head-mounted display has been proposed in which an image indicated by content data is presented to a user's eye so that the image can be viewed, and the image is recognized by the user. For example, in an image display device having a head-mounted display (Head-Mount-Display) body that is a head-mounted image display device that is used in the vicinity of a user's eyeball, and a control unit, the image determination unit includes: When the image displayed on the display unit is determined to be a line image, and the display color determination unit determines that the display color of the background of the line image is white, the display control unit sets the background display color to black, characters, and There has been proposed a technique for controlling the operation of the black and white reversing unit so that the display color of the line is white and the brightness of each line is reversed. (For example, refer to Patent Document 1).

JP 2008-116704 A

By the way, while power saving of various electric products is required, it is necessary to reduce the power consumption of the head mounted display. For example, the head mounted display may be used while moving, in which case it is driven by a battery. Head mounted displays driven by various power sources including battery drive require a long-time display due to power saving. Here, when reducing the power consumption, the visibility of the content image indicated by the content data must not be impaired, and the presentation of the content image that ensures the visibility and the reduction of the power consumption are realized at the same time. There is a need.

This disclosure is intended to provide a new head-mounted display capable of reducing power consumption while ensuring the visibility of content images presented to the user's eyes.

The head mounted display according to the present disclosure determines whether a partial image included in a content image is a line image or a non-linear image, and emits image light indicating a non-linear image that is emitted in units of pixels forming the content image. Is output with an output value corresponding to an output output value lower than the output output value when the image light indicating the line image is output. The head-mounted display of the present disclosure is intended for a light-emitting image element (for example, organic EL (Organic Electroluminescence), LED (each pixel is configured by an individual LED)), or a scanning image forming method. For example, it does not include a configuration employing a non-light-emitting image element such as liquid crystal and a light source that illuminates the image element.

According to the present disclosure, it is possible to obtain a new head mounted display capable of reducing power consumption while ensuring the visibility of the content image presented to the user's eyes.

According to one aspect of the present disclosure, a head-mounted display that allows a user to visually recognize a content image indicated by content data, the partial image included in the content image that emits light in units of pixels that form the content image An image presentation unit that emits image light indicating the image, a determination unit that determines whether the partial image is a line image indicated by a line drawing, or a non-line image indicated by a non-line drawing, and the determination unit includes a line image When it is determined that the image is an image, the image presentation unit is controlled to output image light indicating the line image with an output value corresponding to the first output value, and the determination unit is determined to be the non-linear image. In this case, the image presentation control means for controlling the image presentation means to emit the image light indicating the non-linear image at an output value corresponding to a second emission output value lower than the first emission output value. When, it is possible to obtain a head-mounted display, characterized in that it comprises a.

In such a head mounted display, the output output value of image light indicating a non-linear image can be reduced. For example, the total amount of output power can be reduced as compared with a case where the entire content image is output with an output value corresponding to the first output output value. At this time, the line image, which is character information having a higher importance in the content image, has a relatively high output and is bright, so that visibility can be ensured.

According to another aspect of the present disclosure, the image presentation control unit is configured to display an image indicating the line image in a state in which image light indicating a non-linear image is output with an output value corresponding to the second output output value. In the case of emitting light, the emission output value is an output value corresponding to the first emission output value, and in the state of emitting image light indicating a line image with an output value corresponding to the first emission output value, When emitting image light indicating a non-linear image, it is possible to obtain a head-mounted display characterized in that the emission output value is an output value corresponding to the second emission output value. In such a head mounted display, the output power value can be appropriately changed.

According to still another aspect of the present disclosure, the head mounted display includes a detection unit that can use a battery as a driving power source and detects a remaining battery level, and the image presentation control unit includes the detection unit. When the battery remaining amount value detected by the control unit is less than a predetermined remaining amount value, the output of the image light by the output value corresponding to each of the first emission output value and the second emission output value is controlled, and the detection means When the detected battery remaining amount value is greater than the predetermined remaining amount value, the output of the image light indicating the line image and the image indicating the non-linear image are output according to the output value corresponding to the predetermined output value. It is possible to obtain a head mounted display characterized by controlling light emission. In such a head mounted display, power consumption can be reduced when the remaining battery level is low, and long-time driving can be realized.

It is a figure which shows the state which mounted | wore the head mounted display. It is a figure which shows the functional block of a head mounted display. It is a figure which shows an image presentation apparatus. It is a figure which shows the flow of a main process. It is a figure which shows the flow of a power saving image data generation process. (A) And (b) is a figure explaining a scanning image. It is a figure explaining a laser output value.

Embodiments reflecting the present disclosure will be described in detail below with reference to the drawings. The present disclosure is not limited to the configurations described below, and various configurations can be employed in the same technical idea. For example, in the following description, a head mounted display (hereinafter referred to as “HMD”) in which a head mounted display main body and a control device that executes various processes are integrated will be described as an example. Can be configured as a separate device.

(Overview of HMD)
As shown in FIG. 1, the HMD 100 includes a frame 110 that is worn on the user's head and an image presentation box 130 that presents a content image to be visually recognized by the user. A frame 110 shown in FIG. 1 is formed in a shape similar to a frame of eyeglasses. The frame 110 is not limited to this shape, and may have a helmet shape or the like, and may have another structure that can be mounted on the user's head. An image presentation box 130 including an image presentation device 20 described later with reference to FIG. 2 is disposed in front of the user's left eye. The image presentation box 130 is attached to a predetermined position of the frame 110. The HMD 100 shown in FIG. 1 has a configuration in which one image presentation box 130 is disposed, but may be configured in a manner in which another image presentation box 130 is disposed in front of the user's right eye.

Although details will be described later, the image presentation device 20 in the image presentation box 130 emits image light. The emitted image light is reflected in the direction of the user's left eye by a half mirror which is not drawn in FIG. 1, and is directly applied to the user's eyeball. Thereby, the user visually recognizes the content image. The HMD 100 is a see-through HMD that allows a user to visually recognize the outside world through a half mirror.

The HMD 100 is connected to the power controller 400 by a power supply cable 300. Then, power is supplied from a battery (rechargeable battery) 500 integrally formed with the power controller 400 via the power controller 400 to drive the battery. The integrally configured power supply controller 400 and battery 500 are used by being attached to the user's waist or the like, for example.

(Functional block of HMD)
As shown in FIG. 2, the HMD 100 includes a control unit 12 that controls the device itself, and a storage unit 14 that stores content data 142. The HMD 100 includes an operation unit 16 that is operated by a user and receives an instruction from the user, and an input / output I / F (Interface) 18. Furthermore, the HMD 100 includes an image presentation device 20 that emits image light. Note that each of these components included in the HMD 100 is provided inside the image presentation box 130 (inside the casing constituting the image presentation box 130).

Here, the control unit 12 includes, for example, a CPU that executes various arithmetic processes, a ROM that stores various programs, and a RAM as a work area. Further, the control unit 12 includes, for example, a GPU (Graphics Processing Unit) that executes rendering processing and the like based on a command from the CPU. The memory | storage part 14 is comprised by the non-volatile memory, for example. The content data 142 stored in the storage unit 14 includes, for example, a landscape image of a work place as shown in FIG. The operation unit 16 is configured by, for example, a key, and receives, for example, instructions to start and end playback of the content data 142. The input / output I / F 18 receives supply of power, and transmits and receives various signals to and from the power controller 400 that supplies and shuts off the power (power) to the HMD 100.

The image presentation device 20 can be configured using a retinal scanning display. The image presentation device 20 using the retinal scanning display scans the image light based on the content image data obtained by the rendering process performed on the content data 142 in a two-dimensional direction, and the scanned image light is scanned. It leads to the user's left eye and forms a content image on the user's retina. The image presentation device 20 may be configured to use an organic EL (Electro-Luminescence) display, an LED display, or other light emitting devices in addition to a retinal scanning display. These image presentation devices 20 emit image light emitted in units of pixels forming a content image. The content image includes, for example, the above-described landscape image, in other words, a non-linear image, for example, a line image indicated by a line such as a character, a table, or a diagram explaining the landscape image. Hereinafter, the image presentation apparatus 20 using a retinal scanning display will be described as an example. The content image data generated by rendering the content data 142 is also referred to as “scanned image data”, and the content image represented by the content image data is also referred to as “scanned image”.

The control unit 12 executes a program related to reproduction (rendering) of the content data 142 stored in the ROM that constitutes the controller 12 on the RAM, and generates scanned image data representing a scanned image formed by a plurality of pixels. The control unit 12 determines whether the partial image included in the scanned image is a line image or a non-line image by executing a program stored in the ROM on the RAM. And the image presentation apparatus 20 is controlled so that emission of the scanning image light based on the determination result is executed. Therefore, the control unit 12 uses various data such as the content data 142 and executes various programs stored in the ROM on the RAM, thereby configuring various functional units (for example, determination unit, image presentation control unit). The

(Configuration of image presentation device)
As shown in FIG. 3, the image presentation device 20 includes a scanning image light generation unit 21, a collimating optical system 22, a horizontal scanning unit 23, a vertical scanning unit 24, a relay optical system 25, and a relay optical system 26.

The scanned image light generation unit 21 is a device that reads the image signal output from the control unit 12 for each dot clock and modulates the intensity according to the read image signal to generate the scanned image light. The scanned image light generation unit 21 includes a signal processing circuit 211, a light source unit 212, and a light combining unit 213.

The signal processing circuit 211 is connected to the control unit 12. Based on the “image signal” input from the control unit 12, the signal processing circuit 211 outputs each image signal of B (blue), G (green), and R (red) that is an element for generating scanned image light. 214 a to 214 c are generated and output to the light source unit 212. The signal processing circuit 211 is connected to a horizontal scanning control circuit 23b of the horizontal scanning unit 23 described later. The signal processing circuit 211 generates a horizontal drive signal 215 based on the “image signal” input from the control unit 12, and outputs the horizontal drive signal 215 to the horizontal scanning control circuit 23b. Further, the signal processing circuit 211 is connected to a vertical scanning control circuit 24b described later. The signal processing circuit 211 generates a vertical drive signal 216 based on the “image signal” input from the control unit 12, and outputs the vertical drive signal 216 to the vertical scanning control circuit 24b.

The light source unit 212 includes a B laser driver 212a, a G laser driver 212b, an R laser driver 212c, a B laser 212d, a G laser 212e, and an R laser 212f. The B laser driver 212a drives the B laser 212d based on the B (blue) image signal 214a output from the signal processing circuit 211 for each dot clock. The B laser 212d emits intensity-modulated blue laser light based on the B (blue) image signal 214a. Similarly, the G laser 212e and the R laser 212f emit green laser light and red laser light, which are respectively intensity-modulated.

Each of the lasers 212d to 212f includes a semiconductor laser and a solid-state laser with a harmonic generation function. When a semiconductor laser is used, the drive current is directly modulated to modulate the intensity of the laser beam. That is, the laser light emitting element capable of direct modulation is suitable for power saving because the current can be reduced to about the laser oscillation threshold while the light is not emitted. When using a solid-state laser with a harmonic generation function, each of the lasers 212d to 212f is provided with an external modulator to modulate the intensity of the laser light. However, the efficiency of harmonic generation is not high, the laser output is normally controlled to be constant, and a loss in the external modulator is also added, so that the power consumption of the solid-state laser with a harmonic generation function increases. Since the solid-state laser with a harmonic generation function is not suitable for power saving even if the laser light output is reduced by an external modulator, the solid-state laser itself continues to oscillate at a constant output and is not suitable for power saving. It is necessary to use a laser that can be directly modulated, such as a semiconductor laser.

The light combining unit 213 includes collimating optical systems 213a to 213c, dichroic mirrors 213d to 213f, and a coupling optical system 213g. The collimating optical systems 213a to 213c are disposed in front of the lasers 212d to 212f, respectively. The collimating optical systems 213a to 213c collimate the laser beams emitted from the lasers 212d to 212f. The dichroic mirrors 213d to 213f are disposed in front of the collimating optical systems 213a to 213c, respectively. The dichroic mirrors 213d to 213f selectively reflect or transmit only the laser light having a wavelength in a predetermined range from the respective laser beams collimated by the collimating optical systems 213a to 213c.

The coupling optical system 213g is disposed in front of the dichroic mirror 213d. Blue laser light transmitted through the dichroic mirror 213d and green laser light and red laser light reflected from the dichroic mirrors 213e and 213f are incident on the coupling optical system 213g. The coupling optical system 213 g collects the laser beams of the three primary colors and enters the optical fiber 27. Note that white can be expressed by equalizing the intensity of each of the blue laser light, the green laser light, and the red laser light.

The horizontal scanning unit 23 and the vertical scanning unit 24 generate scanning image light by scanning the laser light in the horizontal direction and the vertical direction in order to irradiate the laser light incident on the optical fiber 27 as an image.

The horizontal scanning unit 23 includes a resonant deflection element 23a, a horizontal scanning control circuit 23b, and a horizontal scanning angle detection circuit 23c. The laser light incident on the optical fiber 27 is collimated by the collimating optical system 22 and is incident on the resonant deflection element 23a. The resonant deflection element 23a has a reflection surface 23d that is swung by the horizontal scanning control circuit 23b. The resonant deflection element 23a reflects the incident laser beam on the oscillating reflecting surface 23d and scans in the horizontal direction. The horizontal scanning control circuit 23b generates a driving signal for swinging the reflecting surface 23d of the resonance type deflection element 23a based on the horizontal driving signal 215 output from the signal processing circuit 211. The horizontal scanning angle detection circuit 23c detects a swing state such as a swing range and a swing frequency of the reflection surface 23d of the resonant deflection element 23a based on the displacement signal output from the resonant deflection element 23a. A signal indicating the swing state is output to the control unit 12.

The vertical scanning unit 24 includes a deflection element 24a, a vertical scanning control circuit 24b, and a vertical scanning angle detection circuit 24c. The deflection element 24a has a reflection surface 24d that is swung by the vertical scanning control circuit 24b. The deflecting element 24a reflects the incident laser beam on the oscillating reflecting surface 24d, scans it in the vertical direction, and outputs it to the relay optical system 26 as two-dimensionally scanned image light. Based on the vertical drive signal 216 output from the signal processing circuit 211, the vertical scanning control circuit 24b generates a drive signal for swinging the reflecting surface 24d of the deflection element 24a. Based on the displacement signal output from the deflection element 24a, the vertical scanning angle detection circuit 24c detects a swing state such as a swing range and a swing frequency of the reflection surface 24d of the deflection element 24a, and detects the swing state. The signal shown is output to the control unit 12.

The relay optical system 25 is disposed between the resonant deflection element 23a and the deflection element 24a. The relay optical system 25 converges the laser beam scanned in the horizontal direction on the reflection surface 23d of the resonance type deflection element 23a and makes it incident on the reflection surface 24d of the deflection element 24a.

The signal processing circuit 211 outputs the horizontal drive signal 215 and the vertical drive signal 216 to the horizontal scanning control circuit 23b and the vertical scanning control circuit 24b, respectively, based on the “image signal” input from the control unit 12, and the reflecting surface. The scanning angles 23d and 24d are controlled.

The scanning angles of the reflecting

surfaces

23d and 24d thus changed are detected as detection signals by the horizontal scanning angle detection circuit 23c and the vertical scanning angle detection circuit 24c, and the detection signals are input to the control unit 12, and the horizontal drive signal 215 and This is fed back to the vertical drive signal 216.

The relay optical system 26 includes

lens systems

26a and 26b having a positive refractive power. The image light emitted from the deflection element 24a is converted into convergent image light by the lens system 26a so that the respective image lights have their center lines substantially parallel to each other. The converged image light is converted into substantially parallel scanned image light by the lens system 26b, and is condensed so that the center line of the scanned image light converges on the pupil Ea of the user's eye E.

In the present embodiment, the laser light incident from the optical fiber 27 is scanned in the horizontal direction by the horizontal scanning unit 23 and then scanned in the vertical direction by the vertical scanning unit 24. The arrangement of the vertical scanning unit 24 may be changed, and after the vertical scanning unit 24 scans in the vertical direction, the horizontal scanning unit 23 scans in the horizontal direction.

(Main process)
The main process shown in FIG. 4 is performed by the control unit 12 executing a program stored in the ROM. The control unit 12 that has started this process first detects the remaining battery level of the battery 500 via the power controller 400 and acquires the remaining battery level value (S100). Subsequently, the control unit 12 determines whether or not the acquired battery remaining value is equal to or less than a predetermined value that is a predetermined constant value (S102). As a result of the determination, when the remaining battery level is not less than or equal to the specified value (S102: No), the control unit 12 proceeds to S104, while when the remaining battery level is equal to or less than the specified value (S102: Yes) The process proceeds to S108.

In S104, the control unit 12 sets a laser output value (emission output value) of scanning image light (specifically, laser light) emitted from the image presentation device 20 to a predetermined default value P (a predetermined constant value). The output power value is set to a value lower than the maximum laser output value. Then, the control unit 12 renders the content data 142 and generates scanned image data (S106). Here, the scanned image data generated in S106 is data representing a scanned image having a brightness corresponding to the default value P of the laser output set in S104. As described above, the scanned image is formed by a plurality of pixels. Therefore, in S106, the control unit 12 scans the scanned image data in which each pixel is set to brightness (gradation) obtained by multiplying the value (coefficient) corresponding to the default value P of the laser output and the brightness value of each color. Generate. For example, when represented by R (red), G (green), and B (blue), each pixel is set to an RGB value corresponding to the default value P of the laser output. Here, the brightness of the pixel (RGB value) and the laser output value are generally correlated. For example, when each of R (red), G (green), and B (blue) is low (in RGB values, the maximum value of each color is 255 in the case of 256 gradations), the laser output value Also lower. In the HMD 100 of the present embodiment, the coefficient when the laser output is the maximum value is 1, and the coefficient when the laser output is the minimum value (not output) is 0, and a predetermined value is associated with each laser output value in the middle. For example, the registered table is stored in the storage unit 14. A value (coefficient) corresponding to the default value P is selected from this table based on the default value P. Hereinafter, description will be made by taking RGB values as an example.

In S108, the control unit 12 sets the laser output value to a predetermined value and stores it in a predetermined area on the RAM. Subsequently, power saving image data generation processing is executed (S110). The laser output value set in S108 is used in the power saving image data generation process (see FIG. 5) in S110. For example, the laser output value set in S108 is a value lower than the default value P. Details of the power saving image data generation processing executed in S110 will be described later.

In S112, the control unit 12 controls the image presentation device 20 to emit scanning image light indicating the scanning image represented by the scanning image data generated in S106, or represented by the scanning image data generated in S110. Scanning image light indicating the scanning image is emitted. Here, the laser output value of the emitted scanning image light is directly modulated with the scanning image data. Therefore, for a dark image, for example, a pixel with a low RGB value, the laser output value of the scanned image light is reduced. Such a configuration is preferable because the laser output value is changed by control when the scanning image light is emitted. However, when the scanning image light is emitted, the line drawing unit or the non-line drawing unit (see S200 (see FIG. 5) of the power saving image data generation process described below) is specified (determined), and the laser output value is controlled. It is also possible to adopt a configuration that changes according to

(Power-saving image data generation processing)
Next, the power saving image data generation process executed in S110 of the main process described above will be described with reference to FIG. The control unit 12 that has started this process firstly includes a line drawing unit including a line image (for example, a character or a line drawing (line)) in a content image indicated by the content data 142, and a non-line image (for example, a landscape drawing). The content data 142 is divided into a line drawing part and a non-line drawing part.

In S200, the control unit 12 may determine a character or a line drawing (line drawing unit) based on the file type of the content data 142. For example, when the content data 142 is a text file, the control unit 12 determines that the content data 142 is a line drawing unit. Further, if the RGB value pairs of the pixels forming the content image are widely distributed in various value pairs, it can be determined as a non-line drawing portion because there is a halftone. On the other hand, when the RGB value pairs are divided into two groups having greatly different values, and one of the pairs is not long and continuous, it can be determined as a character or a line drawing (line drawing portion). Even if it is divided into a plurality of groups, it can be determined that the character or line drawing has a different color unless one set and the other set are long and continuous. When two or more sets are continuous for a long time, it can be determined that there is a non-linear image with a region painted in that color. The continuous length may be determined by whether it is longer or shorter than the normal line width (several pixels). Further, the line drawing unit specified by the control unit 12 may be either a region matching the outline of the line image or a region including the line image (for example, a rectangular region). The same applies to the non-line drawing part.

Subsequently, the control unit 12 determines whether or not there is a line drawing part, specifically, whether or not the line drawing part is divided in S200 (S202). As a result of the determination in S202, when there is no line drawing part (S202: No), the control unit 12 moves the process to S212. On the other hand, if there is a line drawing part (S202: Yes), it is determined whether or not the line drawing part is binary data (S204). When the line drawing unit is binary data (S204: Yes), the control unit 12 moves the process to S208. On the other hand, if the line drawing unit is not binary data (S204: No), in other words, if it is color data, binarization processing is executed on the line drawing unit (S206), and the process is performed in S208. Migrate to Here, the binarization processing is processing for converting color data into gray data and converting the data into binary data using a predetermined threshold.

In S208, the control unit 12 performs the black and white reversal process on the area including the line drawing part in which S204 is affirmed or the line drawing part in which the binarization process in S206 is executed. Here, the black-and-white reversal process is, for example, a process of converting the color of a portion indicated by a line such as a character to white while converting the color of other portions to black.

Subsequently, the control unit 12 renders the line drawing unit in which S208 is executed, generates line drawing unit processed image data (S210), and shifts the processing to S212. In S210, for example, the control unit 12 generates line drawing part processed image data having an RGB value corresponding to a laser output value (first emission output value) equal to or greater than the above-described laser output default value P (see S104 in FIG. 4). . The generation of the line drawing section processed image data is performed by the same method as S106 in FIG. 4 described above based on the laser output value equal to or greater than the default value P. A value (coefficient) corresponding to the laser output value equal to or greater than the default value P is selected from the above-described table based on the laser output value equal to or greater than the default value P.

In S212, the control unit 12 determines whether or not the non-line drawing unit is divided in S200. As a result of the determination, if there is no non-line drawing part (S212: No), the control part 12 moves the process to S218. On the other hand, when there is a non-line drawing part (S212: Yes), the control part 12 acquires the laser output value stored on the RAM in S108 of the main process shown in FIG. 4 (reading / S214). And the control part 12 performs rendering with respect to a non-line drawing part, and produces | generates non-line drawing part process image data. At this time, the control unit 12 generates non-line drawing processed image data of RGB values corresponding to the laser output value (second emission output value) acquired in S214. The process of S216 is executed in the same manner as S106 of the main process of FIG. 4 described above. The value (coefficient) corresponding to the laser output value acquired in S214 is selected from the table described above based on the acquired laser output value.

After executing S216, the control unit 12 combines the line drawing processed image data generated in S210 and the non-line drawing processed image data generated in S216 to generate one scanned image data (S218). . Here, when the determination in S202 is negative (S202: No), the non-line drawing portion processed image data generated in S216 becomes the scanned image data as it is. If the determination in S212 is negative (S212: No), the line drawing section processed image data generated in S210 becomes the scanned image data as it is.

In the above description, the case where the laser output value stored in the RAM in S108 in FIG. 4 and acquired in S214 in FIG. 5 is lower than the default value P has been described as an example. However, a different configuration can be adopted. For example, the laser output value stored in S108 of FIG. 4 and acquired in S214 of FIG. 5 may be higher than the default value P if it is set lower than the laser output value used in S210 of FIG. As compared with the case where the entire scanned image is emitted with the laser output value used in S210 of FIG. 5, power saving can be realized.

(Scanned image and laser output)
The content image indicated by the content data 142, in other words, FIG. 6A showing the image before conversion by the power saving image data generation processing shown in FIG. 5, and the power saving image data generation processing shown in FIG. A comparison with FIG. 6B showing the scanned image represented by the scanned image data will be described.

6A and 6B, as shown in FIG. 5, the region including the character “work place scenery” as a line image, in other words, the region excluding the landscape image (non-line image) is shown in FIG. 5. As a result of executing S208 of the power saving image data generation process, the black and white are reversed. Specifically, the black character “work place scenery” is converted to white, while the background is converted from white to black. Regarding the laser output described later, the scanning image light is not emitted when the pixel is black, and therefore the laser output value is zero.

Further, the landscape image shown in FIG. 6B is converted into a dark image as a whole as compared with the landscape image shown in FIG. This is S216 of the power saving image data generation process shown in FIG. 5 and is stored in the RAM in S108 of the main process shown in FIG. 4 and is acquired in S214 of FIG. 5 (default value P (FIG. 4). This is based on the execution of the process corresponding to the lower laser output).

Changes in the laser output value when the scanning image light indicating the scanning image represented by the scanning image data generated by the main processing shown in FIG. 4 is emitted will be described with reference to FIG. In the graph showing the laser output value in the upper part of FIG. 7, the solid line (described as “this method” in FIG. 7) is the scan generated in S <b> 110 of FIG. 4 (see the power saving image data generation process shown in FIG. 5 for details). A laser output value when scanning image light based on image data is emitted is shown. On the other hand, the broken line (described as “comparison method” in FIG. 7) indicates the laser output value when the scanning image light based on the scanning image data generated in S106 of FIG. 4 is emitted. The laser output value shown in the upper part of FIG. 7 was scanned on a line drawn in the scanned image shown in the lower part of FIG. 7 (a horizontal line that crosses the vicinity of the upper and lower central parts when viewed in front). The change of the laser output value at the time is shown.

As is clear from the laser output value shown in FIG. 7, the comparison method has substantially the same laser output value in the entire scanning range, whereas the laser output value of this method is in the range of a landscape image (non-linear image). While it is lower than the comparison method, it is increasing in the range of the character “work place” (line image). That is, the user of the HMD 100 presented with the image according to the present method visually recognizes a dark landscape image and bright characters as compared with the case of the comparison method.

In addition, according to the structure of this method of this embodiment, in the state which has emitted the scanning image light (scanning image light which concerns on the pixel which forms a non-linear image) which concerns on non-linear images, such as a landscape image, a character etc. When the scanning image light relating to the line image (scanning image light relating to the pixels forming the line image) is emitted, the laser output value increases. On the other hand, when the scanning image light related to the line image is changed to the scanning image light related to the non-line image, the laser output value decreases. When the semiconductor laser is directly modulated, the larger the laser output value, the larger the current needs to flow, resulting in higher power consumption. It can be seen that the area obtained by integrating the solid line, which is the present method, is smaller than the area obtained by integrating the dotted line in the upper part of FIG. Furthermore, since the peak output of the character portion is larger in the solid line and brighter than the comparison method, the visibility of the character, which is more important information, is rather improved.

(Advantageous effects based on the configuration of the present embodiment)
The HMD 100 of this embodiment is stored in the RAM in S108 of the main process shown in FIG. 4, and the laser output value acquired in S214 of the power saving image data generation process shown in FIG. 5 is used in S210 of FIG. A configuration that is set lower than the laser output value is adopted. Therefore, compared with the case where the pixels forming the scanned image represented by the scanned image data are RGB values corresponding to the laser output values used in S210, power saving can be realized without impairing visibility. it can.

Further, for example, if the laser output value used in S210 of FIG. 5 is set to the default value P or less, the laser output value stored in the RAM in S108 of FIG. 4 and acquired in S214 is the laser output value of S210. Therefore, power saving can be realized as compared with the case where the pixels forming the scanned image represented by the scanned image data are RGB values corresponding to the default value P.

Claims

A head-mounted display that allows a user to visually recognize a content image indicated by content data,
Image presentation means that emits light in units of pixels forming the content image and emits image light indicating a partial image included in the content image;
Determining means for determining whether the partial image is a line image shown by a line drawing or a non-line image shown by a non-line drawing;
When the determination means determines that the image is a line image, the image presentation means is controlled to emit image light indicating the line image at an output value corresponding to a first emission output value, and the determination means Image presentation control for controlling the image presentation means to emit image light indicating the non-linear image at an output value corresponding to a second emission output value lower than the first emission output value when it is determined that the image is an image. A head-mounted display.
When the image presentation control means emits image light indicating the line image in a state where the image light indicating the non-linear image is output with an output value corresponding to the second output output value, the output value is output. An output value corresponding to the first output output value is set, and image light indicating the non-linear image is output in a state in which image light indicating a line image is output with an output value corresponding to the first output output value. 2. The head mounted display according to claim 1, wherein the output output value is an output value corresponding to the second output output value.
The head mounted display can use a battery as a power source for driving,
It has a detection means to detect the remaining battery level,
When the battery remaining amount value detected by the detecting unit is less than a predetermined remaining amount value, the image presentation control unit is configured to output image light based on output values corresponding to the first emission output value and the second emission output value. When the battery remaining amount value detected by the detecting means is greater than a predetermined remaining amount value, the image light indicating the line image is output with an output value corresponding to the predetermined output value. The head-mounted display according to claim 1, wherein emission of image light and emission of image light indicating the non-linear image are controlled.