Display device

A display device includes a body including a stationary portion and an extendible portion movable relative to the stationary portion, an expandable display portion having a display area, an adjustable resistor, and a controlling unit. The first end of the expandable display is engaged in the stationary portion, and an opposite second end of the expandable display is engaged in the extendible portion. The adjustable resistor has a resistance varying with a distance between the stationary portion and the extendible portion. The controlling unit is configured for adjusting a size of the display area according to the resistance of the adjustable resistor.

BACKGROUND

1. Field of the Invention

The present invention relates to display technology, and particularly, to a display device.

2. Description of Related Art

Generally, an aspect ratio of a display area of a display device is constant. If images of different sizes (e.g., aspect ratios of 1:1, 4:3, and 16:9), are displayed in full screen mode on the display area, the image is distorted to fit the display area; if the image is displayed in its original size, the display area may not be fully utilized or part of the image may be cropped.

What is needed, therefore, is to provided a display device that can satisfactorily display images of different sizes thereon.

SUMMARY

The present invention relates to a display device. The display device includes a body including a stationary portion and an extendible portion movable relative to the stationary portion, an expandable display portion having a display area, an adjustable resistor, and a controlling unit. The first end of the expandable display is engaged in the stationary portion, and an opposite second end of the expandable display is engaged in the extendible portion. The adjustable resistor has a resistance varying with a distance between the stationary portion and the extendible portion. The controlling unit is configured for adjusting a size of the display area according to the resistance of the adjustable resistor.

Other advantages and novel features of the present invention will become more apparent from the following detailed description of present embodiments when taken in conjunction with the accompanying drawings, in which:

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made to the figures to describe the present embodiments in detail.

Referring toFIGS. 1,2,4, and5, a display device10, according to a first present embodiment, is shown. The display device10includes a body100, an expandable display portion160having a display area162, an adjustable resistor200, and a controlling unit180. The display device10is a portable display area, such as a communication terminal, a digital still camera, or a camcorder.

The body100includes a stationary portion120and an extendible portion140movable relative to the stationary portion120. The stationary portion120includes a front surface122(understood as a surface facing a user), and a rear surface124(understood as a surface away from the user) opposite to the front surface122. Further, the stationary portion120is provided with a plurality of keys126on the front surface122of the stationary portion120for the user to operate the display device10.

Referring toFIGS. 1 and 2, the stationary portion120further includes two guiding rails130extending along a same direction parallel to a moving direction of the extendible portion140, and a first rotating shaft128. The guiding rail130is provided with three engaging protrusions134(e.g., a left engaging protrusion134, a middle engaging protrusion134, and a right engaging protrusion134along a direction from the stationary portion120to the extendible portion140, only the left engaging protrusion134is shown inFIG. 2) arranged along a extending direction of the guiding rail130on a bottom surface132of the guiding rail130. In this present embodiment, each engaging protrusion134is a segmented protrusion.

An axial direction of the first rotating shaft128is approximately perpendicular to the extending direction of the guiding rail130. It is to be understood that a terminal of the first rotating shaft128runs through a gear wheel (not shown) driven by a motor (not shown) in the display device10. Therefore, the first rotating shaft128is driven by the motor to rotate.

Referring toFIGS. 1,2, and3, the extendable portion140includes two guiding rods142(only one guiding rod142is shown inFIGS. 2 and 3) extending along a same direction parallel to the extending direction of the guiding rail130, and a second rotating shaft146. An axial direction of the second rotating shaft146is approximately perpendicular to the extending direction of the guiding rod142. The two guiding rods142are received (at least partially received) in the two guiding rails130, and guided by the two guiding rails130respectively. An engaging recess144is defined in a sidewall143of the guiding rod142facing the bottom surface132of the guiding rail130, and corresponding to the left engaging protrusion134. Therefore, the engaging recess144can fittingly engage with the engaging protrusions134. Beneficially, the two guiding rods142are elastic for easily engaging the engaging recess144with the engaging protrusion134, and separating the engaging recess144from the engaging protrusion134, when the extendable portion140moves relative to the stationary portion120.

The expandable display portion160is rectangular. A first end164of the expandable display portion160is engaged in the stationary portion120, and an opposite second end166of the expandable display portion160is engaged in the extendible portion140. In this present embodiment, the first end164of the expandable display portion160is wrapped around the first rotating shaft128of the stationary portion120, and the second end166of the expandable display portion160is wrapped around the second rotating shaft146of the extendible portion140, as shown inFIG. 3. The display area162of the expandable display portion160faces the user.

Referring toFIGS. 2, and4, the adjustable resistor200is a film resistor in this present embodiment. The adjustable resistor200has a resistance varying with a distance between the stationary portion120and the extendable portion140. The adjustable resistor200includes a resistor body (not shown), a movable contact (not shown), an adjustable portion220, and three pins240. The resistor body and the movable contact are received in the adjustable resistor200, and the adjustable portion220is electrically connected to the movable contact. A terminal of the middle one of three pins240is a central pin244connected to the movable contact, and another terminal of the central pin244is connected to the controlling unit180. A terminal of each of the other two pins242is connected to a terminal of the resistor body, and another terminal of each pin242is connected to the controlling unit180. A terminal of the first rotating shaft128is coupled to the adjustable portion220of the adjustable resistor200. For example, a rectangular recess222is defined in the adjustable portion220, and a rectangular protrusion (not shown) is provided on a terminal of the first rotating shaft128, and engages with the rectangular recess222. Therefore, when the first rotating shaft128rotates, the adjustable portion220is rotated via engagement between the rectangular recess222and the rectangular protrusion so as to change resistance of the adjustable resistor200. Alternatively, a terminal of the second rotating shaft146may be coupled to the adjustable portion220instead.

Each engaging protrusion134acts as a stage. When the extendible portion140is pulled from the stationary portion120, the guiding rod142of the extendible portion140slides along the guiding rail130of the stationary portion120. The engaging recess144engages with the left engaging protrusion134as a first stage, with the middle engaging protrusion134as a second stage, and with the right engaging protrusion134as a third stage.

Referring toFIGS. 1,4and5, the controlling unit180is configured for adjusting a size of the display area162according to the resistance of the adjustable resistor200. The controlling unit180is built into the display device10, and reads a voltage between one of the pins242and the central pin244of the adjustable resistor200. For a resistance varying between one of the pins242and the central pin244of the adjustable resistor200, the voltage therebetween is changed correspondingly. A plurality of reference voltages is pre-set in the controlling unit180. The number of the pre-set voltages is at least the same as the number of the stages. In this present embodiment, the number of the pre-set voltages is three. The controlling unit180controls a size of the display area162of the display portion160according to the voltage of the adjustable resistor200read by the controlling unit180.

Detail Description of the Display Device10Follows.

As mentioned above, three engaging protrusions134(the left engaging protrusion134, the middle engaging protrusion, and the right engaging protrusion) act to provide three stages. Correspondingly, three reference voltages V1, V2, and V3are pre-set in the controlling unit180. The voltage V1is a voltage of the adjustable resistor200read by the controlling unit180when the left engaging protrusion134engages with the engaging recess144, the voltage V2is a voltage of the adjustable resistor200read by the controlling unit180when the middle engaging protrusion134engages with the engaging recess144, and the voltage V3is a voltage of the adjustable resistor read by the controlling unit180when the right engaging protrusion134engages with the engaging recess144. A distance between two engaging protrusions134adjacent to each other is dependent on a changeable length of the display area162of the expandable display portion160between two stages.

Initially, the left engaging protrusion134engages with the engaging recess144. The controlling unit180reads the voltage V1of the adjustable resistor200. Correspondingly, the controlling unit180controls an aspect ratio of the display area162of the expandable display portion160to be 1:1 (e.g., 12×12 centimeters), as shown inFIG. 1.

When an image with aspect ratio of 4:3 is displayed on the display area162, the user may pull the extendible portion140out from the stationary portion120(as shown inFIG. 6) in a manner that the engaging recess144is separated from the left engaging protrusion134, and engages with the middle engaging protrusion134so as to lengthen the display area162of the expandable display portion160(e.g., from 12 centimeters to 16 centimeters). The controlling unit180reads a voltage V2of the adjustable resistor200, and controls the display area162to display for a ratio of 4:3 (e.g., 16×12 centimeters). That is, the 4:3 image is displayed in a full screen mode without distortion thereof.

When an image with a ratio of 16:9 is displayed on the display area162, the user may pull the extendible portion140out from the stationary portion120(as shown inFIG. 7) in a manner that the engaging recess144is separated from the middle engaging protrusion134, and engages with the right engaging protrusion134so as to further lengthen the display area162of the expandable display portion160(e.g., from 16 centimeters to about 21.3 centimeters). The controlling unit180reads a voltage V3of the adjustable resistor200, and controls the display area162to display at 16:9 (e.g., 21.3×12 centimeters). That is, the 16:9 image is displayed in a full screen mode without distortion thereof.

Sizes of the expandable display portion160and the display area162change due to a movement of the extendible portion140and a changeable voltage of the adjustable resistor200read by the controlling unit180to fit a size of the image. Therefore, images of different sizes can be displayed satisfactorily.

Referring toFIG. 8, a display device10′ according to a second present embodiment, is shown. Differences between the display device10′ and the display device10are that a plurality of engaging recesses134′ are defined on a bottom surface132′ of each guiding rail130′, and each guiding rod142′ is provided with a engaging protrusion144′ on a side wall143′ of each guiding rod142′ facing the bottom surface132′ of each guiding rail130′, and corresponding to the engaging recesses134′. Advantages of the second present embodiment are similar to that of the first present embodiment.