JPH1164971A - Shutter mechanism for liquid crystal projector and shutter opening/closing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a mechanism for driving a shutter for protecting the front surface of a liquid crystal projector, with a motor. SOLUTION: The shutter mechanism for the liquid crystal projector is provided with a shutter plate 2 which is for switching the closure and exposure of a lens body 60 for projecting an image and slid in a perpendicular orthogonally crossing the projection direction of the lens body 60. The shutter plate 2 is driven to open/close by a motor unit 4 arranged in the liquid crystal projector 5 and the motor unit 4 is provided with the motor M1 and linked with the shutter plate 2 through a gear train. A slip mechanism 7 for preventing the transmission to the shutter plate 2, of the power of the motor M1 in a state where the sliding of the shutter plate 2 is completed, is provided in the gear train. The motor unit 4 is connected to a control circuit for continuing the rotation of the motor M1 for a specified time, to idle the slip mechanism 7, after the motor M1 is energized and then, the time needed to complete the opening/closing of the shutter plate 2 lapses as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter mechanism for covering a projection lens in a liquid crystal projector and a shutter opening / closing method.

[0002]

2. Description of the Related Art FIG. 14 is an overall perspective view of a conventional liquid crystal projector. As is well known, the liquid crystal projector (5) projects a lens body (60) from an opening (10) on the front surface and irradiates an image from the lens body (60). The lens body (60) is slidable in the front-rear direction of the liquid crystal projector (5). When the liquid crystal projector (5) is not used, a cap (69) for protecting the lens is provided at the tip of the lens body (60). Put on. However, there is a possibility that the cap (69) may be dropped and lost during transportation of the liquid crystal projector (5). In view of this, FIG.
A liquid crystal projector (5) shown in (a) and (b) has been proposed. In this case, a lens body (60) is housed in a cabinet (50), and shutter plates (2) and (2) for switching the exposure and closing of the lens body (60) are provided on the front surface of the cabinet (50). The shutter plates (2) and (2) are manually opened and closed by the lens body (60).
When the lens is used, the shutter plates (2) and (2) are opened sideways to expose the lens body (60).

[0003]

In the liquid crystal projector (5) shown in FIGS. 13 (a) and 13 (b), it takes time and effort to manually open and close the shutter plates (2) and (2), which is inconvenient. Accordingly, the applicant has conceived of driving the shutter plates (2) and (2) with a motor, and has also simplified the mechanism for driving the shutter plates (2) and (2). An object of the present invention is to simplify a mechanism for driving a shutter by a motor.

[0004]

The shutter mechanism of the liquid crystal projector includes a shutter plate (2) that slides in a vertical plane perpendicular to the projection direction of the lens body (60), and the lens body (60) that projects an image. Switch between blockage and exposure. Shutter plate (2)
Is driven to open and close by a motor unit (4) provided in a liquid crystal projector (5). The motor unit (4) has a motor (M1) and cooperates with a shutter plate (2) through a gear train. In the gear train, there is provided a slip mechanism (7) for preventing transmission of the power of the motor (M1) to the shutter plate (2) when the sliding of the shutter plate (2) is completed. Motor unit
(4) The motor (M1) is energized and then the shutter plate (2)
After the time required to complete the opening and closing of the
A control circuit (8) for continuing the rotation of (M1) and idling the slip mechanism (7) is connected.

[0005]

[Operation and effect] Even after the opening and closing of the shutter plates (2) and (2) is completed,
The control circuit (8) keeps rotating the motor (M1) in the motor unit (4) for a certain time. However, even if the motor (M1) continues to supply the power for sliding the shutter plate (2), the transmission of the power to the shutter plate (2) is prevented by the slip mechanism (7). Therefore, even if the motor (M1) continues to rotate after the opening and closing of the shutter plates (2) and (2), the shutter plate (2) is not damaged, and the opening and closing of the shutter plates (2) and (2) is completed. In addition to ensuring reliability, components such as a switch for detecting completion of closing of the shutter plates 2 can be omitted, and the configuration of the shutter mechanism is simplified.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of the present invention will be described in detail with reference to the drawings. The same components as those of the related art are denoted by the same reference numerals, and detailed description thereof is omitted. 1 and 2 are perspective views of the liquid crystal projector (5). A front panel (1) is attached to the front of the liquid crystal projector (5), and an opening (10) is opened in the center of the front panel (1). A pair of shutter plates that open left and right inside the opening (10)
(2) (2) is provided. Behind the shutter plate (2),
A lens body (60) is provided, and as described later, the lens body (60)
Protrudes outward from the opening (10) when the shutter plates (2) and (2) are open (see FIG. 2). On the front panel (1), a light receiving unit (51) for remote control is provided above the opening (10), and when a signal is input to the light receiving unit (51), the shutter plate (2) ( 2) is driven.

FIG. 3 is an exploded perspective view of a mechanism for holding the shutter plates (2) and (2), and FIG. 4 is a liquid crystal projector of FIG.
FIG. 5 is a side sectional view taken along line AA of FIG. On the back side of the front panel (1), an opening through which the lens body (60) can pass
The holder plate (3) having the opening (39) is attached, and the shutter plates (2) and (2) are sandwiched between the front panel (1) and the holder plate (3). In view of the external design, the front panel (1) is formed in a substantially arc shape bulging toward the front, and a boss (11) to which the holder plate (3) is attached from the upper back side of the front panel (1). Is protruding. At the lower end of the front panel (1), a receiving piece (12) extending along the longitudinal direction of the front panel (1) is provided. Is attached. The motor unit (4) has a pair of worms (41) and (42) separated from each other and attached to a shaft (40) extending from the motor (M1). The twist angle is reversed. The tip of the shaft (40) is supported by a bearing (13) (see FIG. 8) erected on the receiving piece (12). motor
When (M1) rotates, shaft (40), worm (41) (42)
Rotate together. The motor unit (4) is a motor (M1)
The shutter plates (2) and (2) are slid by the rotation of (2), the details of which will be described later.

The holder plate (3) is provided with upper recesses (30) and (30) and lower recesses (31) which bulge backward and extend left and right, and a rail plate (32) is attached to the front panel (1) from the lower end. Protruding toward. The lower ends of the shutter plates (2) and (2) are received by the rail plate (32), and the shutter plates (2) and (2) slide left and right. From the back surface of each shutter plate (2), a switch pressing piece (21) and a rack piece (20) with the tooth surface facing downward project from the shutter plate (2).
(21) is in the upper recess (30) (30), and the rack piece (20) is in the lower recess.
(31) is fitted into each (see FIG. 4). Notches (33) and (33) at the lower end of the lower recess (31) to allow the tooth surface of the rack piece (20) to be exposed.
Are provided at two locations. On the back side of the holder plate (3), the pivot (35) is located below the notch (33), and the mounting boss (34) is located above the notch (33) from the lower recess (31). It stands upright.

FIG. 5 is a rear view showing a state in which shutter plates (2) and (2) and a holder plate (3) are attached to the front panel (1). FIG. 6 is a cutaway view of FIG. FIG. 7 is a sectional view taken along line CC. As shown in FIG.
A first meshing gear (70), a second meshing gear (71) and a compression spring (72) are inserted into the pivot (35). A bracket (36) is attached to the mounting boss (34), and the bracket (36) is pivoted (35).
To prevent the compression spring (72) from jumping out. Second
The meshing gear (71) is pressed against the first meshing gear (70) by a compression spring (72), and usually the first meshing gear (70) and the second meshing gear (71).
Rotate together due to friction. As shown in FIGS. 5 and 7, two notches (37) and (37) are provided at the upper end of the upper concave portion (30).
The circuit board (38) protrudes inward from each of the notches (37) (37). An open detection switch (SW1) is attached to the lower surface of each circuit board (38). The opening detection switch (SW1) is turned on by being pushed by the switch pressing piece (21) of the shutter plate (2) when the opening of the shutter plate (2) is completed.

FIG. 8 is a plan view showing the positional relationship between the motor unit (4), the first meshing gear (70), and the second meshing gear (71). As shown in FIGS. 8 and 6, each second meshing gear (71)
Meshes with the worms (41) and (42) of the motor unit (4),
The first meshing gear (70) meshes with the rack piece (20) of the shutter plate (2). Worm (41) (42) receiving rotation of motor (M1)
Rotates, the second meshing gear (71) rotates, and the compression spring (7) rotates.
The first meshing gear (70) pressed against the second meshing gear (71) by 2)
Also rotate. The motor (M1) is connected to a control circuit (8) via a bus line (80) to receive control of the rotation operation, and the control circuit (8) receives the signal of the open detection switch (SW1). Is done.

(Shutter opening / closing) Shutter plate shown in FIG.
(2) An operation when (2) is opened from a closed state will be described. The signal from the external remote control unit is
When the motor (M1) rotates in the opening direction of the shutter plates (2) and (2), the worms (41) and (42) rotate, and
The meshing gear (71) rotates. As described above, the warm (41) (4
2) Since the twist angles are opposite to each other, the second meshing gear
(71) and (71) rotate in opposite directions. Second meshing gear (71)
The first meshing gear (70) pressed against the shutter rotates by friction, and slides the rack pieces (20) in a direction away from each other, and
(2) Open (2). As shown in FIG. 9B, each shutter plate
The switch pusher (21) of (2) opens and the detection switch (SW1) opens
Is pressed, the opening completion state of both shutter plates (2) and (2) is detected, so that the power supply to the motor (M1) is stopped. The shutter plates (2) and (2) are pressed against a stopper (not shown) on the rail plate (32) to maintain the open state. When the shutter plates (2) and (2) are completely opened, the lens body (60) passes through the opening (10) of the front panel (1) and the liquid crystal projector
It protrudes outside from the front surface of (5) (see FIG. 11 (b)).

This embodiment is characterized by an operation when closing the shutter plates (2) and (2). This operation will be described with reference to the flowchart of FIG. First, from the open state shown in FIG. 9B, the motor (M1) is energized to rotate the second meshing gears (71) and (71) in the closing direction of the shutter plates (2) and (2) (S1).
1). When the first meshing gears (70) and (70) rotate in the closing direction of the shutter plates (2) and (2), each switch pressing piece (21) separates from the opening detection switch (SW1) and is shown in FIG. 9 (a). As described above, the side edges of the shutter plates (2) and (2) come into contact with each other (S2). Shutter plate (2)
(2) cannot slide further in the closing direction. However, since a signal to the effect that the shutter plate (2) is closed is not input to the control circuit (8), the control circuit (8) keeps rotating the motor (M1) (S3). The rotation of the motor (M1) causes the second meshing gear (7
1) rotates, but the rotation of the first meshing gear (70) meshing with the shutter plate (2) in the closing direction of the shutter plates (2) and (2) is restricted. Here, since the second meshing gear (71) is pressed against the first meshing gear (70) by the compression spring (72),
The second meshing gear (71) only makes a slip rotation on the first meshing gear (70), and the first meshing gear (70) does not rotate. That is, the rotation of the first meshing gear (70) is restricted by the first meshing gear (70), the second meshing gear (71) and the compression spring (72) in the closed state of the shutter plates (2) and (2). And a slip mechanism (7) for performing the operation.
After the control circuit (8) rotates the motor (M1) in the closing direction of the shutter plates (2) and (2), after a lapse of time sufficient for the shutter plates (2) and (2) to close, the motor (M1) rotates. The power supply to (M1) is stopped (S4, S5). That is, even if the motor (M1) continues to rotate the second meshing gear (71) after the shutter plates (2) and (2) are closed, the first meshing gear (70) is not damaged, and the shutter plate is not damaged. (2) No component such as a switch for detecting the completion of closing in (2) is required. Therefore, the configuration of the shutter mechanism is simplified.

When the shutter plates (2) and (2) are completely opened, both of the open detection switches (SW1) and (SW1) are pushed in, but the worms (41) and (42) and the second meshing gear (71). There is a risk that one of the shutter plates (2) opens earlier than the other shutter plate and pushes the detection switch (SW1) due to backlash or the like. However, when the control circuit (8) detects that only one of the opening detection switches (SW1) is pressed, the motor (M1) is further rotated in the opening direction of the shutter plate (2), The shutter plates (2) and (2) are completely opened. Since the shutter plate (2) which has already pushed the opening detection switch (SW1) is pressed against the stopper on the rail plate (32), it can no longer slide in the opening direction.
The meshing gear (71) and the first meshing gear (70) constitute a slip mechanism, and the rotation of the second meshing gear (71) is not transmitted to the first meshing gear (70), so that the shutter plate (2) is damaged. I won't let you.

After the shutter plate (2) is opened, the lens body (6)
0) protrudes from the opening (10), and as a mechanism for extending and retracting the lens body (60), those shown in FIGS. 11 (a) and 11 (b) are generally used. That is, a lens barrel (6) is rotatably provided in a support barrel (61) located in a liquid crystal projector (5), and the tip of the lens barrel (6) is received by a support plate (62). ing. A connecting shaft (63) connected to the lens body (60) is provided in the lens barrel (6).
Are fitted so as to be able to come and go freely, and the connecting shaft (63) extends and contracts with the rotation of the lens barrel (6). A standby detection switch (SW2) is provided on the side of the rotation transition road of the lens barrel (6), and the standby detection switch is provided on the lens barrel (6).
A recess (65) into which the anvil (64) of (SW2) fits is provided. The state shown in FIG. 11A in which the lens body (60) is housed in the liquid crystal projector (5) is called a collapsed state. In the collapsed state, the standby detection switch (SW2) is turned on by the lens barrel.
It is pushed into the peripheral surface of (6) and turned ON.

When the liquid crystal projector (5) is energized, the motor (M1) is first energized to open the shutter plates (2) and (2), and then the lens barrel (6) is opened as shown in FIG. By rotating the lens, the lens body (60) is projected from the liquid crystal projector (5). This state is called a standby state, and the lens body (60) is temporarily stopped in the standby state. After this, zoom and focus adjustments are performed, and a screen (not shown)
Projection to the camera. FIGS. 12A, 12B and 12C are views of the lens barrel 6 viewed from the direction D in FIG. In the retracted state, as described above, as shown in FIG.
The standby detection switch (SW2) is pushed into the peripheral surface of the lens barrel (6). In the standby state, as shown in FIG. 12 (b), the rotation of the lens barrel (6) causes
The recess (65) of the lens barrel (6) is the standby detection switch
The anvil (64) of the standby detection switch (SW2) fits into the recess (65) facing the (SW2). The standby detection switch (SW2) is turned off, and it is detected that the standby state has been reached. More lens body from standby state
In order to perform the zoom and focus operations by projecting (60), the lens barrel (6) is rotated from the standby state, as shown in FIG. After the use of the liquid crystal projector (5), in order to retract the lens body (60), the reverse operation is performed, and then the shutter plates (2) and (2) are closed.

The description of the above embodiments is for the purpose of illustrating the present invention and should not be construed as limiting the invention described in the appended claims or reducing the scope thereof. Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims.

[Brief description of the drawings]

FIG. 1 is a perspective view of a liquid crystal projector with a shutter plate closed.

FIG. 2 is a perspective view of the liquid crystal projector with a shutter plate opened.

FIG. 3 is an exploded perspective view of a front panel, a shutter plate, and a holder plate.

FIG. 4 is a side cross-sectional view of the liquid crystal projector of FIG. 2 taken along line AA.

FIG. 5 is a rear view showing a state where a shutter plate and a holder plate are attached to a front panel.

FIG. 6 is a side cross-sectional view of the front panel of FIG. 5 taken along line BB.

FIG. 7 is a side cross-sectional view of the front panel of FIG. 5 taken along line CC.

FIG. 8 is a plan view of a motor unit, a first meshing gear, and a second meshing gear.

9A is a rear view of a state where a shutter plate is closed, and FIG. 9B is a rear view of a state where the shutter plate is closed.

FIG. 10 is a flowchart showing an operation when the shutter plate is closed.

11A is a plan view showing a collapsed state, and FIG. 11B is a plan view showing a state where a lens body protrudes from a liquid crystal projector.

FIGS. 12A and 12B are views of the lens barrel of FIG. 11 viewed from a direction D, wherein FIG. 12A shows a retracted state, FIG. 12B shows a standby state, and FIG.

FIG. 13 is a perspective view of a conventional liquid crystal projector.
(a) shows a state where the shutter plate is closed, and (b) shows a state where the shutter plate is opened.

FIG. 14 is a perspective view of another conventional liquid crystal projector.

[Explanation of symbols]

 (2) Shutter plate (4) Motor unit (5) Liquid crystal projector (7) Slip mechanism (60) Lens body (70) First meshing gear (71) Second meshing gear

Claims (3)

[Claims] 1. A liquid crystal projector comprising a shutter plate (2) that switches between closing and exposure of a lens body (60) for projecting an image and slides in a vertical plane perpendicular to the projection direction of the lens body (60). In the shutter mechanism, a shutter plate (2) is driven to open and close by a motor unit (4) provided in a liquid crystal projector (5). The motor unit (4) has a motor (M1), and has a gear train. In cooperation with the shutter plate (2) via the gear train, in the gear train, when the opening and closing of the shutter plate (2) is completed,
A slip mechanism (7) for preventing the transmission of the power of the motor (M1) to the shutter plate (2) is provided. The motor unit (4) is energized to the motor (M1) before the shutter plate (2) A shutter mechanism for a liquid crystal projector, characterized in that a control circuit (8) is connected to keep the motor (M1) rotating for a certain period of time after the time required for the completion of opening / closing has elapsed, and to make the slip mechanism (7) idle. 2. A slip mechanism is provided substantially coaxially with a first meshing gear (70) meshing with the shutter plate (2), and is in pressure contact with the first meshing gear (70). Motor (M1)
The shutter mechanism of a liquid crystal projector according to claim 1, wherein the shutter mechanism is formed by a second meshing gear (71) that receives power from the second gear. 3. A shutter plate (2) provided in front of a lens body (60) for projecting an image and sliding in a vertical plane perpendicular to the projection direction of the lens body (60). A motor unit (4) provided in a liquid crystal projector (5), comprising a motor (M1) for transmitting power to the motor unit;
A shutter plate disposed between the shutter plate (4) and the shutter plate (2);
When the sliding of (2) is completed, the motor to the shutter plate (2)
And a slip mechanism (7) for preventing power transmission from (M1), and rotating the motor (M1) in the opening / closing direction of the shutter plates (2) and (2). After the lapse of time, the motor (M1) is rotated for a certain
(7) A method of opening and closing the shutter of the liquid crystal projector that makes the idle rotation.