# US 5,708,881 A · Camera display device with reduced display time

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,708,881 A
- Document ID: US5708881A
- Status: Granted
- Kind: A
- Application number: 08/343,977
- Filed: 1994-11-18
- Granted: 1998-01-13
- Earliest claimed: 1993-12-01
- Assignees: Nikon Corporation
- Inventors: Daiki Tsukahara; Tadashi Ohtani
- Web page: https://patentgrep.com/patent/US5708881A

## CPC

- G03B 17/18: Signals indicating condition of a camera member or suitability of light (indicating depth of field G03B13/30)
- G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D)

## Abstract

A needle-type display device for displaying photographic data in a camera, the display device including a display having indicating needles which move directly from displaying presently displayed values to displaying new values without temporarily returning to an origin position. The display device includes a half-press switch having first and second positions, and a rangefinder and photometric unit which operate when the half-press switch is in the first position. The display displays photographic data measured by the range finder and photometric unit according to an amount of movement from an origin position by the respective indicating needles. When the half-press switch switches to the second position, a hold command unit operates to hold the respective indicating needles for a predetermined period of time at the display position displaying the measured amount. When a new measurement is performed by the rangefinder or photometric unit during the hold period, an update command unit moves the indicating needles directly from their present positions to new positions without returning to their origins. By the indicating needles moving directly to new display positions, the time required for the display needles to move is reduced, and a quick display response to measured photographic data is possible.

## Claims

### Claim 1

A camera display device having an indicating needle for displaying photographic data, comprising:
a switch having a first position and a second position;
a measuring device to measure photographic data when the switch is in the first position;
a display to display the photographic data measured by the measuring device according to an amount the indicating needle moves from an origin position;
a hold command unit, operating when the switch switches from the first position to the second position, to hold the indicating needle at a present display position indicating the measured photographic data for a predetermined period of time, and to return the indicating needle to the origin after the predetermined period of time; and
an update command unit, to move the indicating needle directly from the present display position to a new display position when the switch switches from the second position to the first position during the hold period and a new measurement of photographic data is performed.

### Claim 2 (depends on 1)

A camera display device as recited in claim 1, further comprising a timer, operatively coupled to the hold command unit, to time the predetermined period of time after the switch switches from the first position to the second position.

### Claim 3 (depends on 2)

A camera display device as recited in claim 2, wherein the timer starts when the switch switches from the first position to the second position, and the measuring device performs the new measurement of photographic data when the switch switches from the second position to the first position before the timer times out.

### Claim 4

A camera display device, comprising:
a switch having an ON position and an OFF position;
a measuring device to measure photographic data when the switch is in the ON position;
a display, including an indicating needle and a display scale, to display photographic data measured by the measuring device according to a position pointed to by the indicating needle on the display scale;
a timer to time a predetermined period of time, starting when the switch switches from the ON position to the OFF position and ending when the timer times out;
a hold command unit, operating when the switch switches from the ON position to the OFF position, to control the indicating needle to hold at a first display position for the predetermined period of time, and to control the indicating needle to return to an origin position after the predetermined period of time; and
an update command unit, to control the indicating needle to move directly from the first display position to a second display position when the switch is switched ON during the hold period and a new measurement of photographic data is performed.

### Claim 5 (depends on 4)

A camera display device as recited in claim 4, wherein the measuring device measures photometric data and range data.

### Claim 6 (depends on 4)

A camera display device as recited in claim 4, wherein the indicating needle rotates.

### Claim 7 (depends on 4)

A camera display device as recited in claim 4, wherein the display includes a plurality of indicating needles and corresponding display scales, the measuring device measures a plurality of photographic data, and the hold command unit and the update command unit operate to hold and update, respectively, the positions of the respective indicating needles.

### Claim 8 (depends on 4)

A camera display device as recited in claim 4, wherein the measuring device measures at least two different types of data, the display includes at least two indicating needles and corresponding display scales displaying the at least two different types of measured data, and the hold command unit and update command unit operate in parallel to hold and update, respectively, the at least two indicating needles.

### Claim 9

A display device comprising:
a measuring device to measure data;
a display including an indicating needle and a display scale, the indicating needle pointing to the display scale to display data measured by the measuring device; and
a control unit, operatively coupled to the measuring device and to the display, to control the indicating needle to display first measured data in response to a first measurement of data by the measuring device, to hold the indicating needle at a position displaying the first measured data for a predetermined period of time and to control the indicating needle to move directly from the position displaying the first measured data to a position displaying second measured data in response to a second measurement of data by the measuring device when the indicating needle is at the position displaying the first measured data.

### Claim 10 (depends on 9)

A display device as recited in claim 9, wherein the control unit returns the indicating needle to an origin position after the hold period when the second measurement is not performed during the hold period.

### Claim 11 (depends on 10)

A display device as recited in claim 10, further comprising:
a switch, operatively coupled to the measuring device and to the control unit, having a first position and a second position, wherein the measuring device measures the first measured data when the switch is in the first position and the control unit moves the indicating needle to point to a position on the display scale corresponding to the first measured data, and when the switch switches from the first position to the second position the control unit holds the indicating needle at the first display position for the predetermined period of time and then returns the indicating needle to the origin.

### Claim 12 (depends on 11)

A display device as recited in claim 11, wherein the control unit controls the indicating needle to move directly to the position displaying second measured data when the switch switches from the second position to the first position during the hold period.

### Claim 13

A method for controlling a display of data on a display having an indicating needle pointing to positions on a display scale to display data, comprising:
measuring first data and moving the indicating needle to a first display position displaying the measured first data;
holding the indicating needle at the first display position for a predetermined period of time;
measuring second data; and
moving the indicating needle directly from the first display position to a second display position displaying the measured second data when the step of measuring second data occurs during the predetermined period of time during which the indicating needle is held at the first display position.

### Claim 14 (depends on 12)

A method for controlling a display as recited in claim 12, wherein the step of measuring first data comprises:
detecting a switch in a first switch position;
measuring the first data in response to the switch being in the first switch position, and
moving the indicating needle to the first display position to display the first data; and
the step of measuring second data comprises
detecting the switch in a second position, and
measuring the second data when the switch switches from the second switch position to the first switch position while holding the indicating needle at the first display position.
