Display device

Abstract

To provide a drive unit that is compact and can reduce a load generated due to bending of a flexible printed substrate and inhibiting movement of an electrical component.SOLUTION: A drive unit has a rectangular parallelepiped electrical component, a bendable substrate, and a driving section for driving the electrical component. The electrical component includes a first surface, four side faces each adjacent to the first surface, and a second surface opposite to the first surface. A direction in which the electrical component is driven by the driving section and a normal direction of the first surface are parallel to each other. The substrate includes a connection part that is connected with the electrical component on one of the first surface and the second surface, a stationary part that is immovable during movement of the electrical component, and a coupling part that couples the connection part and the stationary part to each other. The coupling part passes through a surface closest to the driving section, of four surfaces including the four side faces, respectively, different from one another.SELECTED DRAWING: Figure 4

Description

Technical Field

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[0001] The present invention relates to a drive device and a display device having the same.

Background Art

[0002] Conventionally, when moving an electrical component with respect to a rigid substrate on which a control board for controlling the electrical component is mounted, a configuration for changing the bending state of a flexible printed board connected to the electrical component and the rigid substrate is known. Patent Document 1 discloses a configuration for reducing a load that inhibits the movement of an electrical component caused by the elasticity of the flexible printed board when the bending state of the flexible printed board changes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration of Patent Document 1, since the flexible printed board is bent multiple times, the system to which the configuration of Patent Document 1 is applied may be enlarged.

[0005] An object of the present invention is to provide a small drive device while being able to reduce a load that inhibits the movement of an electrical component caused by the bending of a flexible printed board.

Means for Solving the Problems

[0006] One aspect of the present invention is a drive device comprising a rectangular parallelepiped electrical component, a flexible substrate, and a drive unit for driving the electrical component. The electrical component has a first surface, four sides adjacent to the first surface, and a second surface facing the first surface. The driving direction by the drive unit is parallel to the normal direction of the first surface. The substrate has a connection portion connected to the electrical component on one of the first and second surfaces, a fixed portion that remains immovable when the electrical component moves, and a connecting portion that connects the connection portion and the fixed portion. The connecting portion is characterized in that each of the four surfaces, each including a different surface of the four sides, passes through the surface closest to the drive unit. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce the load that hinders the movement of electrical components caused by the bending of a flexible printed circuit board, and to provide a compact drive device. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows a schematic configuration of an image display device equipped with a drive device according to an embodiment of the present invention. [Figure 2] This diagram shows the state of the display unit and lens when the display unit is moved. [Figure 3] This is a perspective view showing the configuration of the display unit. [Figure 4] This is a perspective view showing the configuration around the movable part. [Figure 5] This is a top view showing the configuration around the movable part. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. In each drawing, the same reference numeral is used for identical components, and redundant descriptions are omitted.

[0010] The following describes how the drive device according to an embodiment of the present invention can be used for diopter change driving in an image display device, but it may also be used for driving in other devices.

[0011] Figure 1 is a diagram showing a schematic configuration of an image display device 1 equipped with a drive device according to an embodiment of the present invention. The image display device 1 is used, for example, in AR (Augmented Reality) devices, MR (Mixed Reality) devices, and VR (Virtual Reality) devices. The image display device 1 can be used in a form that is worn on the user's head (head-mounted type) or in a form that is worn like glasses (glasses type). In either form, the image display device 1 is fixed near the user's eyes 2 so that the display unit is positioned opposite the user's eyes 2.

[0012] The video display device 1 includes a display control unit 101, a display unit 102, a lens (optical element) 103, an actuator (drive unit) 104, a movable part 105, and a drive control unit 106. In this embodiment, the drive device is composed of a rectangular parallelepiped electrical component included in the display unit 102 (described later), the actuator 104, and a flexible substrate (described later) whose first end is connected to the electrical component and whose second end is connected to the actuator 104. The display unit 102 is held by the movable part 105 and can display images and videos according to the instructions of the display control unit 101, which is an integrated circuit. The lens 103 is positioned opposite the top surface of the electrical component included in the display unit 102. The video displayed on the display surface of the display unit 102 (the top surface of the electrical component) is presented to the eye 2 through the lens 103. The actuator 104 moves the movable part 105 along the direction N normal to the top surface according to the instructions of the drive control unit 106. As the movable part 105 moves, the display unit 102 held by the movable part 105 also moves along the normal direction N. By moving the display unit 102, it is possible to change the diopter when observing the display surface of the display unit 102 through the lens 103.

[0013] Although Figure 1 shows a configuration that displays to one eye of the user, it is possible to display to both eyes of the user by adding one more of these components.

[0014] Figure 2 shows the state of the display unit 102 and the lens 103 when the display unit 102 is moved. Figure 2(a) shows the state when the display unit 102 is moved away from the lens 103. Figure 2(b) shows the state when the display unit 102 is moved closer to the lens 103. When the user observes the display surface of the display unit 102 through the lens 103 with their eye 2, they see a virtual image 107. In this embodiment, the position of the virtual image 107 in the normal direction N with respect to the position of the eye 2 is defined as the virtual image formation position i.

[0015] As shown in Figure 2, when the display unit 102 moves, the virtual image formation position i also moves. For example, as the display unit 102 moves closer to the lens 103, the virtual image formation position i moves further away from the eye 2. Conversely, as the display unit 102 moves further away from the lens 103, the virtual image formation position i moves closer to the eye 2. Therefore, as described above, it is possible to change the diopter by moving the display unit 102.

[0016] In this embodiment, the virtual image formation position i moves away from the eye 2 as the display unit 102 approaches the lens 103, and the virtual image formation position i moves closer to the eye 2 as the display unit 102 moves away from the lens 103. However, the present invention is not limited to this. The virtual image formation position i may be configured to move closer to the eye 2 as the display unit 102 approaches the lens 103, and to move further away from the eye 2 as the display unit 102 moves away from the lens 103.

[0017] Figure 3 is a perspective view showing the configuration of the display unit 102. The display unit 102 comprises a backlight unit 108, which serves as a light source for display, and a liquid crystal panel (electrical component) 109 that can obtain a desired display by switching between transmitting and blocking the light emitted from the backlight unit 108. The backlight unit 108 and the liquid crystal panel 109 are fixed together with an adhesive or the like.

[0018] The liquid crystal panel 109 includes a top surface (first surface) 109a capable of displaying images and videos, four side surfaces 109b, 109c, 109d, 109e each adjacent to the top surface 109a, and a bottom surface (second surface) 109f facing the top surface 109a. A transparent cover glass for protecting the liquid crystal panel 109 may be fixed to the top surface 109a by a method such as an adhesive. The four side surfaces 109b, 109c, 109d, 109e are respectively included in surfaces 110b, 110c, 110d, 110e. The surfaces 110b, 110c, 110d, 110e only need to include the side surfaces 109b, 109c, 109d, 109e respectively, and their respective sizes are not limited to the sizes shown in FIG. 3. A backlight unit 108 is fixed to the bottom surface 109f.

[0019] The flexible printed circuit board 111 is configured to be bendable. The flexible printed circuit board 111 includes a connection portion 111a connected to the liquid crystal panel 109. The liquid crystal panel 109 and the flexible printed circuit board 111 are electrically connected via a conductive adhesive or the like. Therefore, an electrical signal such as an instruction for the operation of switching the transmission and blocking of light performed by the liquid crystal panel 109 can be transmitted to the liquid crystal panel 109 via the flexible printed circuit board 111.

[0020] In FIG. 3, the connection portion 111a is connected to the liquid crystal panel 109 on the top surface 109a, but the present invention is not limited to this. For example, the connection portion 111a may be connected to the liquid crystal panel 109 on the bottom surface 109f. Further, the flexible printed circuit board 111 may also be connected to the backlight unit 108.

[0021] Also, in the present embodiment, the display unit 102 includes the backlight unit 108 and the liquid crystal panel 109, but the present invention is not limited to this. For example, the display unit 102 may include an organic EL display or the like in which an organic EL material is formed on a substrate. In that case, the flexible printed circuit board 111 is connected on one of the top surface and the bottom surface of the substrate (electrical component) of the organic EL display.

[0022] In this embodiment, the electrical component is a component included in the display unit 102, but the present invention is not limited to this as long as it is rectangular in shape. For example, the electrical component may be an image sensor or the like. In this case, the flexible printed circuit board is connected to the image sensor on the bottom surface of the image sensor.

[0023] Furthermore, in this embodiment, the flexible printed circuit board 111 is connected to the electrical component so as to cover a portion of a predetermined side of the electrical component, but the present invention is not limited thereto. For example, the flexible printed circuit board 111 may be connected to the electrical component so as to cover the entirety of a predetermined side of the electrical component.

[0024] Figures 4 and 5 are perspective and top views, respectively, showing the configuration around the movable part 105 that holds the display unit 102. The movable part 105 comprises a movable sheet metal 112 and a friction member 113. The actuator 104 comprises a diaphragm 115 and a piezoelectric element 117.

[0025] The display unit 102 is fixed to the movable sheet metal 112 by attaching the bottom surface 108a of the backlight unit 108 to the adhesive surface 112a of the movable sheet metal 112 using adhesive or double-sided tape.

[0026] The movable sheet metal 112 is provided with a first guide hole 112b and a second guide hole 112c. A first guide member 114b and a second guide member 114c are fitted into the first guide hole 112b and the second guide hole 112c, respectively. The first guide member 114b and the second guide member 114c are fixed to a housing (not shown) and cannot move relative to the housing. The first guide hole 112b is a round hole and, by fitting into the first guide member 114b, restricts the translational movement of the movable part 105 in a plane parallel to the top surface 109a of the liquid crystal panel 109. The second guide hole 112c, by fitting into the second guide member 114c, restricts the rotational movement of the movable part 105 around the first guide hole 112b. With this configuration, the movable part 105 can move only along the normal direction N relative to the housing (not shown).

[0027] The friction member 113 is fixed to the movable sheet metal 112 by attaching its mounting surface 113a to the mounting surface 112d of the movable sheet metal 112 using adhesive or double-sided tape. The friction contact surface 113b of the friction member 113 makes frictional contact with the diaphragm 115 due to the applied pressure (biasing force) 116 acting by a biasing part such as a compression spring.

[0028] The piezoelectric element 117 is attached to the diaphragm 115 with an adhesive or the like. When an ultrasonic signal is applied to the piezoelectric element 117, ultrasonic vibrations are generated in the piezoelectric element 117. At this time, ultrasonic vibrations are also generated in the diaphragm 115, and a driving force 118 is generated. The driving force 118 is transmitted via friction to the friction member 113, which is in frictional contact with two protrusions provided on the diaphragm 115. As a result, the friction member 113 is movable along the normal direction N.

[0029] The drive control unit 106 can change the direction and speed of movement of the friction member 113 by changing the magnitude, frequency, and phase difference of the ultrasonic signal applied to the piezoelectric element 117.

[0030] When the friction member 113 moves due to the ultrasonic vibrations generated in the diaphragm 115, the display unit 102 held by the movable part 105 also moves along the normal direction N.

[0031] Since the friction member 113 is always in frictional contact with the vibrating plate 115 due to the applied pressure 116, the actuator 104 can hold the friction member 113 even when the piezoelectric element 117 is in an unpowered state and no ultrasonic signal is applied to it. Therefore, even when the piezoelectric element 117 is unpowered, the movable part 105 does not move, thus preventing damage to the components due to movement of the movable part 105.

[0032] The rigid substrate 119 is fixed to a housing (not shown). The display control unit 101 and the connector 120 are mounted on the rigid substrate 119. The connector 120 is connected to the display control unit 101 inside the rigid substrate 119. The fixing portion 111b of the flexible printed circuit board 111, shown by the dashed line in Figure 5, is inserted into the connector 120. By inserting the fixing portion 111b into the connector 120, the display control unit 101 and the display unit 102 can be electrically connected. As a result, in this embodiment, the liquid crystal panel 109 can switch between light transmission and light blocking according to the control signal output by the display control unit 101. Consequently, various displays based on the control of the display control unit 101 can be displayed on the display unit 102.

[0033] The fixing portion 111b is inserted into a connector 120 mounted on a rigid substrate 119 which is fixed to a housing (not shown), and therefore remains immobile when the display unit 102 is moved. In this embodiment, the fixing portion 111b is fixed to the housing by being inserted into the connector 120, but the present invention is not limited to this. For example, the fixing portion 111b may be fixed to the housing by being attached to the housing with double-sided tape.

[0034] The flexible printed circuit board 111 includes a connecting portion 111c that connects a connecting portion 111a and a fixed portion 111b. In the flexible printed circuit board 111, the fixed portion 111b is fixed to a connector 120 of a rigid circuit board 119 fixed to the housing, and the connecting portion 111a is fixed to a display unit 102 that moves relative to the housing, and therefore moves relative to the housing. With this configuration, when the display unit 102 moves, the connecting portion 111c deforms. Since the flexible printed circuit board 111 has elasticity that tries to return to its original shape, an elastic force 121 is always generated around the connecting portion 111a. The magnitude of the elastic force 121 changes depending on the deformation state of the flexible printed circuit board 111. Therefore, when the deformation state of the connecting portion 111c changes due to the movement of the display unit 102, the elastic force 121 also changes.

[0035] A rotational moment 122 is generated by the driving force 118 produced by the actuator 104 and the elastic force 121 produced by the flexible printed circuit board 111. When the rotational moment 122 is large, the friction load generated when the guide hole provided in the movable sheet metal 112 and the guide member slide against each other when the movable part 105 moves increases. Also, the possibility of the movable part 105 tilting increases. Since a large friction load increases the power required to move the movable part 105, it is preferable to suppress the friction load. Furthermore, if the movable part 105 tilts, the display unit 102 and the virtual image 107 will also tilt, making it impossible to display the desired image, so it is preferable to suppress the tilting of the movable part 105. Therefore, it is preferable to reduce the rotational moment 122.

[0036] In this embodiment, the connecting portion 111c includes a component side passing portion 111d that passes through the surface 110e, which is the closest surface to the actuator 104 among the four surfaces 110b, 110c, 110d, and 110e. With this configuration, the driving force 118 and the elastic force 121 can be brought closer together, and the rotational moment 122 can be reduced, thereby suppressing frictional load between the guide hole and the guide member and tilting of the movable portion 105.

[0037] Furthermore, large fluctuations in frictional load worsen the controllability of the actuator 104 when moving the movable part 105. As mentioned above, by providing a part side passage portion 111d that passes through the surface 110e closest to the actuator 104 in the connecting portion 111c, the driving force 118 and the elastic force 121 can be brought closer together. Therefore, even if the fluctuations in the elastic force 121 are large, fluctuations in the rotational moment 122 can be suppressed.

[0038] The connecting portion 111c comprises a bent portion 111c1 and an excess length absorbing portion 111c2. The bent portion 111c1 is bent. The excess length absorbing portion 111c2 absorbs the change in the required length of the flexible printed circuit board 111 when the movable portion 105 moves and the distance between the connecting portion 111a and the fixed portion 111b changes.

[0039] In this embodiment, the excess length absorption section 111c2 is S-shaped, but the present invention is not limited to this. The shape of the excess length absorption section 111c2 can be any shape that can absorb changes in the required length of the flexible printed circuit board 111, such as a W-shape.

[0040] The applied force 116 acts in a direction perpendicular to the driving direction by the actuator 104, which is parallel to the normal direction N. If a force parallel to the direction of the applied force 116 were to act, the biasing force generated between the friction member 113 and the diaphragm 115 due to the applied force 116 would become unstable. The driving force 118 generated by the ultrasonic signal applied to the piezoelectric element 117 would also become unstable. As a result, the driving of the movable part 105 by the actuator 104 would become unstable. Therefore, it is preferable to avoid applying a force parallel to the direction of the applied force 116. In this embodiment, the bent part 111c1, the excess length absorbing part 111c2, and the fixed part 111b are arranged in order from the side of the connection part 111a in the driving direction by the actuator 104. As a result, the elastic force 121 generated in the flexible printed circuit board 111 acts in a direction parallel to the driving direction by the actuator 104. Therefore, since the elastic force 121 acts in a direction perpendicular to the direction of the applied pressure 116, the biasing force generated between the friction member 113 and the vibrating plate 115 is stabilized. As a result, the driving of the movable part 105 by the actuator 104 can be stabilized.

[0041] Furthermore, the terms "orthogonal directions" and "parallel directions" are not limited to strictly orthogonal directions or parallel directions, respectively, but also include substantially orthogonal directions (approximately orthogonal directions) and substantially parallel directions (approximately parallel directions).

[0042] Furthermore, the force acting in a direction perpendicular to the driving direction by the actuator 104 does not necessarily have to be the applied force 116. For example, the actuator 104 and the movable part 105 may be connected by a rack connection or the like, and the biasing force acting for this connection may be the force acting in a direction perpendicular to the driving direction by the actuator 104.

[0043] Preferably, the actuator 104 generates a frictional force parallel to the direction of the elastic force 121, even when the piezoelectric element 117 is de-energized, thereby enabling the movable part 105 to be held by friction. When the piezoelectric element 117 is de-energized, a frictional force is generated between the friction member 113 and the diaphragm 115 at the same position where the driving force 118 is generated. If no frictional force is generated, the movable part 105 will move due to the elastic force 121 when the piezoelectric element 117 is de-energized. By generating a frictional force parallel to the direction of the elastic force 121, the actuator 104 can suppress the movement of the movable part 105. When movement of the movable part 105 is unnecessary, the application of ultrasonic vibration to the piezoelectric element 117 can be stopped, and the piezoelectric element 117 can be de-energized, thereby enabling power saving of the video display device 1.

[0044] As described above, the configuration of this embodiment makes it possible to reduce the load that hinders the movement of electrical components caused by the bending of the flexible printed circuit board 111, and to realize a compact drive device. Furthermore, by applying such a drive device to an image display device 1 that allows diopter adjustment when viewing the display unit 102, it is possible to stably perform the diopter adjustment operation and realize an image display device 1 with good viewing quality.

[0045] This embodiment includes the following configuration. (Composition 1) A rectangular electrical component, A flexible substrate and It has a drive unit for driving the aforementioned electrical components, The aforementioned electrical component comprises a first surface, four sides, each adjacent to the first surface, and a second surface facing the first surface. The driving direction by the drive unit is parallel to the normal direction of the first surface. The substrate comprises a connection portion on one of the first and second surfaces that is connected to the electrical component, a fixed portion that remains immovable when the electrical component moves, and a connecting portion that connects the connection portion and the fixed portion. The drive device is characterized in that the connecting portion passes through the surface closest to the drive unit among the four surfaces, each of which includes different surfaces of the four sides. (Configuration 2) The movable part is movable while holding the aforementioned electrical component and is biased by a biasing force in a direction perpendicular to the normal direction, The connecting portion comprises a bent portion and an excess length absorbing portion that absorbs the change in the required length of the substrate due to the movement of the movable portion. The drive device according to configuration 1, characterized in that the bent portion, the excess length absorbing portion, and the fixing portion are arranged in order from the side of the connecting portion in the driving direction. (Composition 3) The movable part is movable while holding the aforementioned electrical component and is biased by a biasing force in a direction perpendicular to the normal direction, The drive unit comprises a piezoelectric element that vibrates when a drive signal is applied, and the drive device according to configuration 1 or 2 is characterized in that it can hold the movable part by friction when the piezoelectric element is in an unpowered state where no drive signal is applied. (Composition 4) A drive device as described in any one of configurations 1 to 3, A display device characterized by including the aforementioned electrical components and having a display unit for displaying an image. (Composition 5) The system further comprises an optical element positioned opposite the first surface, The aforementioned first surface is capable of displaying the aforementioned image, The display device according to configuration 4, characterized in that when the electrical component moves, the diopter observed when the first surface is viewed through the optical element changes. (Composition 6) The display device according to configuration 4 or 5, characterized in that it can be attached to the user so that the display unit is positioned facing the user's eyes. (Composition 7) The display device according to configuration 6, characterized in that it can be attached to the user's head. (Composition 8) The display device according to configuration 6, characterized in that it can be worn by the user like eyeglasses.

[0046] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. [Explanation of Symbols]

[0047] 104 Actuator (Drive Unit) 109 LCD Panel (Electrical Component) 109a Top surface (first surface) 109b, 109c, 109d, 109e Side view 109f Bottom surface (second surface) 110b,110c,110d,110e surface 111 Flexible printed circuit board (PCB) 111a Connection 111b Fixed part 111c Connection part N normal direction

Claims

1. A display device wearable by a user, comprising: A display unit; A bendable substrate connected to the display unit; a drive unit that generates a drive force that moves the display unit in a first direction that intersects with a display surface of the display unit, the drive unit is disposed at a position shifted in a second direction different from the first direction with respect to the display unit, the substrate is fixed at a position closer to a surface of the display unit on which the drive unit is located than to a surface of the display unit on which the drive unit is not located in the second direction, The display device, wherein the substrate extends in the second direction from a connection portion connected to the display portion toward a side where the drive portion is located.

2. The display device according to claim 1, characterized in that the substrate comprises the connection portion, a fixed portion fixed to a member whose distance from the display portion changes when the display portion moves, and a connecting portion connecting the connection portion and the fixed portion.

3. The display device according to claim 2 , wherein the connecting portion is bent in the second direction at a position between the display portion and the drive portion.

4. A display device as described in claim 3, characterized in that the connecting portion is bent between a portion extending from the connection portion in the second direction and a portion extending in the first direction.

5. The connecting portion has both ends bent in the portion extending in the first direction, 5. The display device according to claim 4, wherein a length of the portion of the connecting portion extending in the first direction changes depending on a position of the display portion in the first direction.

6. A display device as described in claim 2, characterized in that the connecting portion deforms depending on the position of the display portion in the first direction.

7. A movable part that holds the display unit and is connected to the drive unit; 2. The display device according to claim 1, further comprising a guide member that fits into a hole provided in the movable portion and guides the movement of the movable portion in the first direction.

8. The display device according to claim 1, characterized in that the first direction is a normal direction of the display unit.

9. The display device described in Claim 1, characterized in that the second direction is the left-right direction of the display device.

10. The display device further includes an optical element disposed opposite a display surface of the display device, 10. The display device according to claim 1, wherein the display unit adjusts visibility when the display surface is observed through the optical element by moving the display unit in the first direction.

11. The display device described in Claim 10, characterized in that the display device is wearable by a user so that the optical element is positioned opposite the user's eye.

Images